Patreon LogoYour support makes Blue Moon possible (Patreon)

Science Gone Wrong...or Right? (Kassy & LordBesar)

Kassyghost

Kassyghost

Star
Joined
Oct 24, 2016
Location
Six feet under the dirt
Kassy Kent stood in her bedroom looking in the mirror at her reflection in the new striped dress she'd purchased. The occasion was the return of her much older brother whom she hadn't seen in almost three years. She'd been only 13 when her brother had gotten the elite internship after finishing his degree in engineering. It was some big medical corporation and after he'd moved away his career had kept him so busy that he hadn't made it home for even a single holiday in almost three years and Kassy and their parents missed him terribly.

Two weeks ago he'd phoned though, telling them that he was taking a sabbatical from work and returning home for a visit. Kassy had been ecstatic, she absolutely idolized her brilliant, handsome older sibling and went right out and bought a new outfit to celebrate. She wanted to look as grown up as she could for him, as the last time he'd visited he'd still called her 'Kiddo' and that drove her absolutely crazy. All she wanted was for him to realize that she'd grown up, but she was only thirteen then, and now she was sixteen and felt like she was twenty. Unfortunately her body didn't agree, she was still nearly flat chested and terribly embarrassed by the fact she was a late bloomer and her reflection only served to reinforce that.

"Kassandra??? Kassy, Honey what are you doing up there? Your brother is going to be here any minute!" Her mother called up from downstairs.

"Nothing... I'll be right down!" Kassy called back, frustration burning in her eyes.

Her father didn't allow her to wear makeup yet and she wished she could wear lipstick but settled for some lip gloss and finished by fixing her hair so that it draped over her shoulder. It would have to do, she thought to herself as she heard the cab pull up out front. Kassy ran to the window and looked down seeing him exit the cab, she felt butterflies flutter in her stomach. She turned and booked down stairs, almost tripping and falling down them.

"KASSY, WHAT THE HELL? HOW MANY TIMES DO I HAVE TO TELL YOU NOT TO RUN DOWN THE STAIRS?! For God's sake you are going to break your neck!" Her father scolded, and his tone only drove home the point that her whole family still regarded her as a child.

"OK, ok....geez...." Kassy grumbled, as she finished sprinting toward the front door. "He's here!" Kassy exclaimed and ripped open the front door, eye wide with excitement.
 
Kevin Kent felt the cab turn off the freeway and down onto the street that led to his childhood home. He hadn't been home in years. Even since he'd moved away after getting the new job as a bio-engineer at a major company. His work was mixed, some for development and research. Other work going towards human production. Drugs and hormones alike. One of the things he'd begun to work on in recent months, was a hormone for fertility. Theoretically, it would allow a woman to become pregnant with a child no matter how barren she had been. Kickstarting her ovaries and turning her into a literal baby factory. But of yet, he'd not managed to get approval for any human testing. Only on lab rats, who had now begun to overwhelm his lab.

He came back home a bit frustrated. Wanting to advance the hormone but unsure how. So he took a month off work and decided to go back home to see his parents and sister. Packing a bag, he booked a flight home and caught a cab at the airport The drive was around forty minutes. And it was already close to dinner time by the time the cab parked in the driveway. Getting his briefcase out of the trunk and slinging it over his shoulder. Grabbing his suitcase with his other hand. Walking up to the door, Kevin chuckled at the sight of Kassy already standing there. Wide eyed and clearly excited.

"Hey there kiddo." he teased. Holding his arms out for her. Gripping her in a tight hug and messing with her hair teasingly. "Miss me huh?"

One arm wrapped around Kassy, Kev walked inside his family home. "Mom!" he called. "Your son is home!"

"So what's going on with you these days? Still tiny it looks like." He teased the young girl. Rubbing Kassy's head like when they were childmren.
 
Kassy was breathless when she saw Kevin coming up the walkway, he was so incredibly handsome, a big strong body and that brilliant mind like the cherry on top of a perfect sundae. She ran toward him, arms spread wide, she engrossed him in a big hug, pressing the tips of her tiny nipples into his six pack abs. But then as quickly as the feeling had entered her it was snubbed out as he called her 'Kiddo' again and tussled her hair like she was still in elementary school. Kassy's cheeks burned red with embarrassment and she fought back tears.

"Geez Kass, get off of him and give him some air, we all missed him!" Her father,Glen scolded, in between puffs on his pipe. "How is it going son? It damn good to see you." He said as he reached out and took his son's luggage, shaking his hand.

"Glen, Let a mother hug her Favorite Son!" Martha exclaimed as she pushed Glen out of the way and smothered her handsome, successful son in hugs and kisses. "Oooh honey you look so good, maybe a little thin, but my dinner should cure that, come in, supper is almost ready." She preened.

Kassy was furious at how they'd pushed her aside, and fumed as her parents doted over Kevin their prodigal son.

"Here Kassy, take your brother's luggage up to his room. Kev, you come on in and have a seat on the couch, you can tell me all about what you've been up to at work." Glen said, tossing his son's suitcase to his daughter and offering to take Kevin's briefcase.

"I'll get both you men, a scotch, you must be whipped after that long flight, sweet heart!" Martha offered.

Kassy stuck her tongue out, but realized that making faces only made her look even more adolescent and quickly retracted it. She reached out and took her brother's briefcase from her father and then took both the bags upstairs, pouting the whole way.

When she reached her brother's room, which their parents had left just the way he'd left it, she flopped the bags onto his bed. First the big suitcase, then as her anger built, she slammed down the briefcase and the unintentional collision of the two, popped the lock on it. The lid sprung open and it's contents sprayed across the room.

"Shit!" Kassy exclaimed, and both her hands came up to cover her mouth. She still almost never swore and even though she as alone in her brother's room her modesty still managed to shame her. Kassy scurried around the bed and started cleaning up her brother's important papers and other random office supplies he had stowed away. It was then she saw the vial of pinkish looking fluid marked as FEFH and underneath the acronym in fine print, Female Enhanced Fertility Hormone .

Kassy stared confused at the test tube of iridescent pink goo, shifting its contents back and forth. She knew her brother was in some sort of genetic engineer field and wondered what the stuff could do. She'd always been far more curious than cautious and right now she thought the words on the vial sounded pretty enticing. Besides, it couldn't be dangerous, if it was they wouldn't have let him out of the lab with it, right?

"A little bit won't hurt, and maybe it'll make those jerks downstairs start realizing that I'm almost an adult..." Kassy mused aloud, popping the corked end open and sniffing the stuff. It smelled like cotton candy, so that was a good sign, right? She pulled it up to her lips, only wanting a tiny taste, but a sudden yell from downstairs caught her by surprise and she ended up dumping the whole thing down her throat.

"KASSY! What's taking so long? Come down and set the table for supper!" Martha yelled.

Kassy coughed, her eyes growing large as she peered down at the now empty vial. "Shoot!" She said, this time remembering her manners. "Oh great how am I going to explain this?" She whimpered.

Kassy dropped the empty vial and crushed it with her babydoll shoes. "I'll just tell him it dropped and broke, he'll be none the wiser." She said as she stood up and started for the door. Her head suddenly began to spin and she had to grab the door jam in order to not tumble over. She took a second to compose herself, chalking it up to over excitement from her brother's return and then made her way downstairs.

"Kev....I got some bad news....You know I'm the biggest klutz in the world...well I kinda dropped yer briefcase and something broke....Soooorry. Don't be mad ok?" She asked in her sweetest, 'don't-be-mad' tone.
 
"Good to see you too dad." Kevin chuckled. Returning his father's hug and then turning to give his mother one. It seemed like everyone was fawning over him. And out of the corner of his eye he saw Kassy frowning. Making a note to speak with her later, he followed his parents and took that drink. Happy to not have any work to worry about for a change. While they relaxed in the living room and he sipped his father's scotch, he thought about his sister. Hoping she was okay.

After drinking two glasses of scotch, Kev was feeling a bit buzzed. When he saw Kassy reappear, something about her expression made him notice. "Uh...what exactly did you break?" He asked. Thinking about the contents of his briefcase. A computer. His work phone. Tablet. Some random other things. And....the vile.

Jumping up, he grabbed Kassy by the shoulders. Much to the shock of his parents. "Kassy, tell me you didn't break the vile." He demanded. Worried that she had. "did you get any of it on you? Tell me no. Otherwise we might need to get you to the hospital right away. That stuff wasn't ready yet, and I'm not sure what will happen if you got any on you."

He awaited her reaction. Worried his little sister had made a huge mistake.
 
"Whaaa? No..no... I didn't get any on me, I cleaned it up with a rag, Geez I said I was sorry don't be too mad." Kassy said, not wanting to lie to her brother, but not wanting to get caught more. Though truth be told, hearing her brother talk about it being NOT ready did make her anxiety raise drastically; atleast that's what she thought it was. Her head was really light and she did feel a little dizzy but did her best to hide it.

"KEVIN?? What the hell are you talking about? You brought something dangerous into my house?" Glen suddenly spoke up, fear and confusion spreading across his face.

"Everybody just calm down, it's fine I said I cleaned it up and I saw another vile that I didn't break, so there is still one more! Please don't be mad at me." Kassy said, putting on her best puppy dog look, batting her eyes and twisting her foot back and forth innocently. She walked over and wrapped her arms around her brother's midsection again. "Forgive me?" She asked, holding his muscular form close to her own. Her body was practically vibrating being this close to him and she had to check herself. She didn't know what was wrong with her, but suddenly she was getting hot flashes.

Kassy forced herself to compose and pulled her self away from Kevin, before turning to her father. "Kevin would never do something like bringing a dangerous genetically engineered serum into the house Daddy. Don't be ridiculous, The label said 'placebo' isn't that right Kev? !" Kassy said trying to calm the tense situation.

"Dinner's ready! Kassy did you set the table?" Their mother called from the other room, still oblivious to the situation.

"Coming Mom" Kassy replied, and then gave her brother a pinch on the butt before skipping off toward the kitchen.
 
Breathing a sigh of relief, Kevin took a deep breath and turned to his father. "Dad, it's alright." He assured Glen. "I had something from work in my briefcase. Nothing deadly. But we haven't tested it yet. And I didn't want Kassy to get hurt if she accidentally got something on her. But we're all good it seems." Once everyone had calmed down, Kevin sighed and returned his kid sister's hug. "It's okay. He assured her. Just as long as you didn't get any on you."

For some reason, it felt like her nipples were as hard as glass. Poking him through the fabric of their outfits. "Yeah dad, it's nothing big." he assured Glen. Coming along with his family to sit down for dinner. Yelping when his sister pinched his ass. "Hey, what was that for?" he asked in shock. She'd always been a terrible tease. Kind of a brat really. But that was something new really.

sitting down on the left hand side of the table by his father, Kevin eyed the meal his mother had made. "Smells great mom." He complimented. "It's been a while since I had a real home cooked meal. I eat at the cafeteria at work most days. And prepared stuff at nights when I'm not at work. So this is nice really."

Starving, he dug in right away. Needing some food as he'd been promised.
 
Kassy sat across from her brother at the table, with her mother sitting next to her. She noticed her head was more than light now, it was positively swimming. She looked down at the delicious meal that Martha had made, but her appetite craved something other than food and she couldn't quite put her finger on it. Instead she just kind of picked at it while her brother discussed how he'd been doing and what he'd been working on.

Normally Kassy would have been completely engaged in the conversation but for some reason she could seem to keep up. She'd always been a straight A student in school, even electing some early college courses but now all the science talk seem to bore her. Many of the big words seemed really foreign to her even though she was sure she knew their meaning, it was like her mind couldn't focus on anything other than the warm vibrating sensation emanating from her lower midsection.

Her mind kept slipping back to the memory of the time she'd accidentally walked in on Kevin and saw the massive piece of man-meat between his legs. It was huge, easily the size of a baby's arm and she found herself fantasizing about it while their parents rattled off question after stupid question.

"Kassy! You are staring and your mouth is hanging open...Are you feeling alright?" Martha suddenly asked, snapping Kassy out of her daydream.

"Huh? Wha? Yeah....uuuuh yeah I'm fine..." Kassy stammered, but realized she sounded like a real dummy. "Go on...I'm just listening to all this smart science... stuff." She tried to cover but her thoughts were still really clouded, almost like she was feeling stupider. 'Wait, is 'stupider' a word?' she mused to herself and shot Kevin a silly smile.

"Go on Kevin finish what you were saying about your research, your sister has obviously caught a case of the 'simpletons'. " Glen said, giving Kassy a disappointed look.

Kassy was feeling even stranger, her dress seemed tight, especially around the chest and she peered down at herself. Her tiny tick tac tits had barely filled the dress just a half hour ago but now the fabric seemed to stretch around the bulbous bumps, her nipples practically poking out through the stitching. She giggled despite her confusion.

Her legs felt warm too, she was rubbing the white stocking covered calves together under the table, feeling the tingling sensation run up and down them, from her toes to her inner thighs. Soon her foot slipped out of the black baby doll shoe and before she could stop herself her leg outstretched and came up between her brother's. Her toes gently tickling his inner thighs and pressing inward. She could see the look of surprise on his face, and giggled again, slipping a finger up to her lips in the sign of 'shhh'.
 
"Basically I've been working on a new supplement that should totally boost male testosterone." Kevin began explaining to his family. Not revealing what Kassy had broken, choosing one of his other projects instead. The project he was explaining was already fast tracked. The FDA had given approval and it would be hitting sale in the next year. He'd already used some personally. And it had turned his already huge cock into a cum guyzer. Every load was like a fountain. Which had made sex difficult, as women were afraid of his huge and potent loads now.

Kassy seemed to be distracting everyone. Something was off about her. But he had no idea what. She'd always been a bit weird. Hanging around him and pestering him for attention. So Kevin paid her little mind. Relating to his parents what he worked on. At least, what he was legally able to say without breaking his confidentiality agreement with the company he worked for.

"I can't mention much more, I'm not allowed to." he revealed after a while. His parents listening intently the whole time. He was just about to mention another thing he'd developed, when he felt the foot running up his thigh. Knowing right away that it had to be Kassy, his eyes flashed over to her. "What on earth is she doing." He thought to himself. Her foot going places it shouldn't. "Uh, I think maybe we should go to the living room and relax." He suggested. "I'm a bit tired and dinner tables aren't the most comfortable."

Whatever was off about Kassy was concerning him. So Kevin wanted to get out from under the table so he could keep her foot away from him.
 
Kassy pouted when her brother suddenly pulled his chair away from the table and suggested the reconvene in the living room. She honestly didn't know what was going on with her, she knew that Kevin was her brother and that making advances toward him was wrong but her mind wouldn't cooperate. Plus she was really starting to feel uncomfortable in her dress, it seemed to be growing tighter by the second, giving her a feeling of claustrophobia.

"Kass are you feeling alright?" Martha asked, seeing the disconcerting look on her daughter's face. "Are you going to help me clear the table while your father and brother relax in the living room?"

"I don't know mom, I'm feeling a little queasy. I think I'm gonna go upstairs and lay down for a while." Kassy answered and excused herself. She made her way to the stairs and quickly upstairs, shooting Kevin a anxious look as she passed by him.

Once the young woman had made it back up into her room she could finally get a look in the mirror and confirm her suspicions, her breasts were definitely bigger, but not just that, she spun around and saw that her butt was also swollen. It's normally small profile was now bulbous and round and pushing the back hem of her dress out and up. "OH MY?!!" She whispered, both confused and uncharacteristically bubbly.

The dress was positively strangling her, and she knew she was going to have to get it off, she reached back and tugged at the zipper but it was jammed do to being overstuffed. "OHHH come on!" She grumbled and tugged harder and eventually it broke free. The constrained force exploding outward and blowing the zipper apart. The dress fell to the floor at her feet and now Kassy really got a good look at how much she'd changed. Sure her boobs and butt looked bigger in the dress, but now they were free she could really see how much she'd grown. Her tiny tits were now large C cups with big pink puffy nipples which stood on end. Meanwhile her normally small ass had popped out like one of those twerking girls on the internet.

"HOLY SHIT!" She exclaimed, not shying away from swearing this time. She stood staring in the mirror at the stripper body she now had and a big smile crossed her face. She couldn't explain it, surely she should be terrified by her bodies sudden transformation but instead she was positively giddy. It was like her body wasn't the only thing that was changing, her mind seemed to be dulling as well.

She knew that Kevin was the only one who could give her advice on this, afterall it was his serum that was at fault. Kassy ran to her closet and tried to find clothes that would fit her new bimbo body, but everything seemed entirely too small. There was a pair of baggy blue jean shorts, but they weren't baggy anymore, now they fit like a pair of too small daisy dukes.There was a white undershirt and she grabbed it and forced her new large breasts into it. She pulled them on and then peered back into the mirror. This would have to do.

She ran to the door and pulled it back open, "KEV!! Can you come up here for a minute?" She called down.
 
Kevin was busy explaining things to his parents. Kassy's actions were indeed worrying him, but he resolved to find out later why she was acting so weird. For now, he didn't want to worry their parents,a at least until he had some time to make sure Kassy was okay. But it was starting to make him wonder if she'd accidentally gotten some of the hormone on her. Just the thought scared him. He'd seen what it did to mice. Turned even the most docile into crazed sex creatures. Constantly mating and never wanting to stop aside from a necessary need for food and rest.

"Get better kiddo." he called to her when she went upstairs to her room. Making himself a mental note to go check on her a bit later. Instead, he went back to telling his parents about his work. His mother had a lot of questions about where he was living. How well he ate. His love life, et cetera. It was starting to grow a bit tiresome. And Kevin was already a bit tired from his flight.

Hearing Kassy call for help made him sigh. "What does she want now." he grumbled. "Let me go check on her." He said to his parents. Getting up and climbing the stairs to go to her room. Knocking on the door before he entered. "Kassy, what the hell..." Suddenly he stopped mid sentence. Kassy was totally different. Just moments ago she had been flat as a board. No tits or ass to speak of. Now she looked like a curvy babe. With a big chest and a matching ass. The shorts making her butt look even bigger. And the tight shirt puffing her chest out more.

"Kassy, did you get any of that hormone on you?" Kevin asked. His face nervous. Worried his kid sister had accidentally dosed herself.
 
"Okay, I'm not gonna lie to you....again. Yeah I did get just a little bit on my finger...and then I accidentally wiped my lips aaannd.... I drank the whole vile of pink stuff....geez" Kassy said, finally coming clean. She should have been embarrassed, and shame filled due to her behavior but instead her normally sharp mind could really only focus on the large bulge in Kevin's pants. Sure he'd had a big dick back when she'd snuck a peek when she was younger, but it couldn't have been as big as the print in his pants implied.

"Look I'm really sorry ok? I was just sick and tired of everyone treating me like a dumb kid and all the girls in my class have already developed and have boyfriends, meanwhile I was still flat chested. So yeah, I saw the label on the vile and I thought it might help me out a little. I was only going to take a tiny sip, but I got spooked when Mom yelled and I accidentally drank the whole thing... Am I going to be ok, Kev? I mean just look at me..." Kassy rambled, trying to keep her mind on topic but her eyes were locked on her brother's crotch.

"It's not just my body either, my mind feels distracted and foggy. I can't focus on anything....on anything....anything other than..." Kassy started to say, but then her prodding instincts took over and she lunged forward, dropping to her knees in front of Kevin and reached up and grabbed the crotch of his pants, gripping his big log with both her hands. "GIMME!" She snarled, her mouth opening and dropping down onto the fabric covering his cock, she started to suck on him through his pants.

Kassy couldn't believe what she was doing, sure she'd always had a kind of school girl crush on her big studly older brother, but never acted upon it. It was immoral, wrong on so many levels, but her mind and emotions wouldn't let her stop, she craved cock and she would have it, right now.
 
"You did what!!!" he almost yelled. Furious that she'd been so careless and let herself drink the hormones. "Kass, that stuff made lab rats turn into sex crazed monsters. The females couldn't get enough to satisfy them. It would have killed the males had we not managed to give them some vitamin boosters in their food. Do you want to know what they started doing all day? Having sex. Constantly. Endless rat mating. And even in their sleep, the females still tried to drain the males dry. That's why I can't get it approved yet. The FDA said it was too dangerous for human use yet, and won't even let us so much as test it on totally willing subjects. "

"I need to get you to a hospital, drain your fluids and hope we can get the stuff out of you before..." suddenly he wasn't able to speak. His kid sister had dropped to her knees and was trying to such his cock from outside his slacks. Being a well endowed man, Kevin was always carrying around a decent length of flesh in his pants. But at the touch of her mouth, it sprung up. Hardening almost instantly. A natural reaction to the stimulation that his now crazed sister was showing. It was possible the hormones had already started acting within her. And that there was no hope for her to reverse back to the flat chested shy girl she'd been.

"Damn Kassy, your mouth feels really fucking good." he grunted. Distracted by her mouth and reaching over to stroke her face. "Ugh, just stop. I don't want this. Your my sister for god's sake! What will mom and dad think if they know you tried to suck my dick!" Pleading with her to stop, Kevin hoped there was still some part of her mind that worked normally. That would allow him to calm her down.
 
Kassy heard her brother's protests and normally they would have struck a chord, she would have never done anything like this before she ingested the serum, but now...

"Ssshhhh Kev, you don't have to make this weird just relax and let me have some of what I need." Kassy whispered, her lips brushing against the big bulge in his pants. He hadn't pushed her away and with her mind in such a flutter she could only fixate on the growing piece of man meat in his trousers.

Kassy reached up and grabbed his belt buckle, ripping it open and then unbuttoning his pants, she reached into his boxer shorts and as soon as her petite hands grabbed a hold of the monster he had stashed inside her eyes grew large with excitement. She looked up into her brother's eyes with disbelief.

"You can't tell me its always been this big...Have you been experimenting on yourself as well?" She asked as she pulled the mammoth cock out and stared directly at the single eyed serpent. Kassy's lips parted and slowly slipped around the head of the big thing, her tongue swirling around it's tip in a circular motion. Kassy had never sucked a cock before, let alone her own brother's, but she immediately felt a wave of pleasure wash over her as her jaw spread wide in order to accommodate it's girth. The tip of Kassy's tongue darted into his urethra and she savored the taste of his precum in her mouth.

"Maybe your potent semen blown down my throat might help counteract the serum...let's give it a try ok?" Kassy said, pulling her brother's cock out only long enough to suggest the notion and then plowing it back down her throat.
 
It was so damned hard to argue with her in that moment. It had been a long time since Kevin had gotten laid last. And his balls were indeed blue with need. Jacking off at night didn't really milk them dry like how he wanted. Only a mouth, cunt or ass would really be able to satisfy the need he had within his loins.

"Fuck you shouldn't be doing this." he growled. But at the same time, he wasn't really working that hard to fight her off. She had turned into a sexy bombshell in just minutes. And the way she seemed to be demanding his dick was just too much to resist.

"haha, actually no. This is all me." He assured her. Still trying to fight the urges she had inflamed within him. "Fuck! Stop that!!" Kevin demanded. Kassy's mouth starting to weaken what little resolve he still had. Already it was just a mild flicker of resistance remaining.

"Ugh, what the hell. Just suck me off and make me blow my loud down your throat." he demanded. Standing there patiently as she began to bob her head up and down on his enormous man meat. Precum starting to leak out and fill her mouth. As much fluid in his pre as a normal man would produce in their actual load. A side effect of the male serum he had tried some time ago.

"Fuck, just make me cum down your tummy Kass!!" Kevin growled, his need starting to build.
 
Kassy giggled when she heard her older brother use the term 'tummy' but the ridiculous terminology didn't stop her from burying his whole cock down her throat. It was amazing, she'd heard some of her more promiscuous friends talk about blowing their boyfriends and they always talked about how trying to take it all would trigger their gag reflex and even one horror story about a girl puking on a prick, but here she was sliding her brother's massive dong down her throat without even a hint of regurgitation. It was like her throat had opened up wide like a gracious host accepting a long overdue guest.

Kassy moaned, letting the vibration from her larynx pulse around his member, she felt as though her clit was in her throat and all she wanted was for him to fuck her face like a pussy. Kassy started jackhammering her own head up and down on Kevin's cock like a girl possessed, slamming her lips against the pubic hair covered base with each thrust. Her hand came up and cupped his balls, squeezing ever so gently as she did so, while the other one reached around an grasp his buttcheek, her nails digging into the flesh. She'd never felt anything so good in her life, any guilt about Kevin being her brother had completely disappeared as she sucked him off.

Kassy's pussy was wet, practically dripping she could feel the crotch of her jean shorts dampen and she wondered how good it would feel to be fucked. Her new large breasts heaved awhen the notion occurred to her, she pulled his cock out of her mouth, ripped off the white shirt and grasp her new large tits by the nipples and slammed them together around his shaft. "I always wanted to try titty fucking!" Kassy exclaimed happily as she stared up into her brother's face. His saliva covered cock slid easily up and in between the breast-cunt she'd created and her mouth acted as the vulva, sucking his head every time it appeared.

"Gimme that goo big boy! Fuck your teenaged sister right in her dirty mouth!" Kassy moaned in ecstasy praying he was going to fill her mouth with his baby batter.

It was just then the heeled shoes of her mother's familiar ascension of the stairs could be heard and Kassy could see the fearful urgency in her brother's face. She should be feeling the same thing, but she wasn't, all she wanted was her brother's cum and she didn't want to let his cock go before she got it.

"Kassy? Kevin? Is everything alright? You two have been up here for a while?" Martha asked, just outside the bedroom door, the doorknob starting to wiggle as she tried to enter.

"Finish motherfucker!" Kassy whispered in a guttural animal like snarl as she hungrily gobbled Kevin's cock back down her throat.
 
"Holy fuck! Where the hell did you learn how to do that!" Kevin asked in complete shock. He'd heard that she was sexual active, but he also knew she didn't have a steady boyfriend. Her sudden deep throat skills were a major surprise. Perhaps a side effect of the hormone she'd ingested. Kevin made a mental note to run some test on her later. After she'd finished face fucking herself on his dick of course.

"You want it, you've got it." he growled. Holding onto the side of her face and fucking her mouth as hard as she had bobbed her head on his dick. "Holy fuck you are such a fucking dick whore. Fine then, earn that dick you slut. You want to be a whore for your brother, then you better fucking make me want to cum down that throat and turn you into a cum whore." His balls were slapping against her chin when she was being face fucking. Heavy loads of cum ready within.

The tit fucking was amazing. Shortly before, Kassy had no tits to speak of. Not even being a decent B cup. Now she was a bombshell with huge tits that Kevin thought were getting even bigger. "Mmm, bimbo bitch." He teased. Groaning as she serviced his dick like a champ.

"Uh, just showing Kass something for her school work. She's not the brightest and just needed some help, we'll be done in just a sec." he replied to his mother. Though the word sec came out more so as sex. A Freudian slip.

"Fine, here it cums bitch." he growled. His load having barely been held back. Suddenly ropes of cum began to shoot. Huge loads of thick and creamy cum. Potent and sticky. "Fucking take it Kass!!!"
 
Kassy giggled with joy as her brother verbally berated her, before ingesting the serum she would have been completely set aback by hearing her beloved older brother call her things like 'bimbo', 'bitch' or 'whore' but now they only seemed to make her more excited. She didn't even feel a tinge of shame as she felt her brother's cockhead swell in her throat while he lied to their mother just on the other side of the door, only lustful wanton.

The girthy beast's mushroom shaped head flared out like a king cobra's hood just before it struck, filling her throat and blocking her airway. The perfect seal ensuring maximum fill, his cock exploded goo. The first few shots, while his balls clenched and his shaft spasmed, seemed to fill her small belly with warm milky goodness. Thankfully she'd been distracted during dinner and barely touched her food, because Kevin was delivering a far more fulfilling meal now. Unfortunately it didn't stop there, he just kept cumming, her stomach's capacity reached, the powerful jizz's back-pressure pushed his penis out of her throat and she erupted like a volcano. Hot thick seed boiled out of her mouth and nose as she gagged to keep the torrent down, but alas it was an act of futility.

Kevin's cum spilled out of her and ran down her chest, covering her big spit covered tits and Kassy reached up and spread the goo around, smiling happily up at Kevin, a look of dumb bliss shining in her eyes. She reached down into her tiny daisy duke shorts and pushed three fingers into her snatch, pumping herself as spine shivering waves of pleasure washed over her. The semen rushed passed her naval and filled in the cup of her masturbating hand, but she could care less about getting pregnant, all she could focus on was how good it felt to be this high on sex.

Unbeknownst to her though, the sudden influx of Kevin's enhanced seed to her already accelerated system kick the super hormone into overdrive. Her body suddenly got hot as the retrovirus started alter her DNA again. Kassy moaned and fell back onto the floor as her spent brother watched on. Her already swollen tits began to swell further, as did her ass and thighs. Her lips swelled and plumped further and much of the remainder of the gleam of intelligence she once showed, seemed to dull almost to nothing.

When Kassy sat back up still covered in her brother's cum, she'd transformed into a total bimbo. "That was fun!! heheh" She giggled like a nit wit.

"It's Saturday Kevin, what sort of Homework are you helping her with? She's a straight A student... Open this door...." Martha persisted from outside in the hall, suspicion growing in her voice.
 
"Oh fuck!!" Kevin grunted as his monster balls dumped a mammoth load into Kassy's tummy. So much cum that her mouth broke like a levee. Dumping the excess anywhere it could go. The sight of his kid sister, busted full of cum and fingering herself like a wanton whore just made Kevin want her more. His cock still rock hard despite having just cum huge buckets of creamy white seed into her. "Uh, that was good." he admitted with defeat. His now clearly bimbofied sister having conquered his resistance with her mouth and tits.

"Oh for god's sake mom, we'll be right out!" he grunted. Pushing Kassy off his dick. "Put on some clothes quick. Something baggy. Those tits are massive and mom and dad will freak. I'll have you checked out soon, but just do what I say."

If Kassy was anything like the lab rats he'd initially tested the hormone on, she was just getting started. The desire for sex would be uncontrollable. And she would no doubt seek him out more and more. So for now, Kevin was going to work on damage control. Calming any suspicions his parents might have.

At the same time though, it wasn't easy to stuff his fat cock back into his pants. But somehow he managed it. Though there was still a huge pipe like bulge down his right pant leg.

"Ready slut?" he barked. Fussing at Kassy.
 
Kassy stood up bobbling, she followed her brother's orders like a well trained stupid slut. She darted to her closet and pulled out a series of outfits but as she held each up in front of her dressing brother, it became obvious that none of these clothes were going to fit her new extremely buxom form. They'd all been bought with she was still petite and flat, and now she was anything but.

"None of these fit, Kevy-wevy, Will you go an buy me some new clothes?" She said in her new high-pitched idiot voice, still massaging the coagulating cum on her tiny stomach with her fingers.

"KEVIN! OPEN THIS DOOR IMMEDIATELY! YOU ARE UPSETTING ME! YOU OPEN THIS DOOR THIS INSTANT OR I'LL GO DOWN AND GET YOUR FATHER!" Martha yelled from out in the hall, jiggling the locked door's knob violently.

"Mom sounds mad....We should dose her with the other thingy of pink stuff..." Kassy giggled stupidly.
 
"For the love of god this is getting nuts." he grumbled. His kid sister was now acting dumb, and his mother wasn't really making things easier. Debating options in his mind, he decided on what might be best.

"No, I'm not going to. Now get under your blankets and act like you're not feeling well!" he barked. Hoping there was some way to get this all to just calm down, Kevin took a deep breath and waited a second. Before opening the door and smiling innocently at his mother.

"She's not feeling well alright? And I was just trying to help her." he shrugged to his mother. Hoping she wouldn't notice the giant pipe of man meat that was hanging low in his pants.
 
Kassy did as instructed, completely oblivious to how upset her brother was, all she could focus on was the stiffened bulge in her brother's pants. She climbed into bed and stuffed her new ill proportioned body under the sheets but that didn't stop her from burying her hand into her sopping wet snatch once she was hidden.

The door came open in a flash once Kevin had unlocked it, Martha burst in, the look of worry on her face. She was greeted by the sight of her daughter in bed while her grown son stood in front of her. "Oh I'm sorry, I don't know what I was thinking..." Martha apologized as she embarrassingly blushed faced dropped realizing now that she'd over reacted. She rushed forward and embraced her son, pulling him close and squeezing him against her. It was then she felt the long, large bulge running down Kevin's thigh and pulled away quickly. "Oh dear...sorry honey." She said apologizing again. She thought it strange, but after over reacting before she didn't want to make another scene.

Martha then rushed over to her 'innocent' bed ridden daughter and sat down. She leaned over and gave her sweet Kassandra a kiss on the forehead drawing a high pitched giggle from Kassy. Martha jerked back violently when she felt the slimy goo that covered Kassy's face. "Oooh dear, you must be sick, you're covered in a flop sweat and your lips look swollen. God I hope it's not some sort allergic reaction to something I cooked." She said as she unknowingly wiped her son's semen's from her lips.

Meanwhile Kassy was nearly wrist deep in her own honey-hole as she rhythmically fisted herself under the covers. "OOOhhh Owwww....Kevy was just helping me get into bed Mommy! I don't feel good, My 'TUMMY' hurts and Kevy was just giving me my medicine." Kassy coed.

"Wha? Medicine....yes...yes..." Martha said trying to make sense of Kassy's moronic ramblings. "Kevin dear would you run to the store and get some anti-histamines from the mall pharmacy...you know just in case it is an allergic reaction." Martha pleaded.
 
Breathing a long sigh of relief, Kevin nodded. His mother had bought it. But the risk of being caught was still strong. He could tell by the rose colored cheeks and movement under the sheets that Kassy was still horny as hell. She would eventually become too horny to even think unless she had a dick in one of her holes. And his appeared to be the dick of choice, otherwise she might have tried to fuck their father already.

"Yeah mom, will do. Can I borrow your car?" he nodded in agreement. Leaving the room and getting her keys. Getting right into his mother's Volkswagen and heading right out to the mall. He knew Kass didn't need any conventional drugs. Only his own research could reverse the effects. But for now, new clothing was needed. So he headed straight for a department store and got to work. It was difficult to judge what sizes she would need. But he guessed that her new ass was larger, so he bought a fist full of sexy panties that would fit her new ass. Mostly thongs. And gambled on two different bra sizes. Getting a few of each.

After that, Kevin grabbed some dresses. The stretchy fabric would allow her to adjust over time. Not to mention the short fabric would show off her new bimbo body. Which he was starting to crave more and more.

Eventually Kevin had several hundred dollars worth of merchandise for Kass. Paying with his rewards credit card. About to leave the mall, he noticed a sex shop and decided to stop in for fun. His eyes drifted over a few things, and Kevin decided to grab a couple of butt plugs. One had a fuzzy bunny tail at the end. The other was stainless steel with a jewel.

Half a grand spent, Kevin finally came home. Thankfully he'd bought some antihystemines too as a cover. Sneaking through the house, he made sure no one would catch him. Slowly heading towards Kassy's room to check on the whore.
 
Kassy was near orgasm again when Kevin finally took his mother's VW and left for the store, while her mother sat vigilantly on her bedside. With Kevin gone from sight and Kassy's needs still not sated, she pulled her free hand from under the sheets and reached out and rubbed her mother's arm.

"Thank you sooo much for sitting with me Mommy, you look really pretty today." Kassy coed as she caressed her mother.

Martha reached out and pressed the back of her hand against her daughter's forehead, she pulled it away instantly as she felt how hot it was. "Oh dear Kass, You are burning up, and moaning like a sick dog...I hope your brother hurries. Maybe I should call the ambulance." She persisted, unaware that Kassy's strange behavior wasn't from any natural fever, but instead a side effect from Kevin's serum.

"No... No I just need my Mommy!" Kassy whined, her hand slipping from her mother's arm and onto the woman's large chest. Her hand dropped down and began to rub the large breast, catching the point of her mother's nipple between her thumb and forefinger and briefly giving it a squeeze.

"Oh Kassy you are delirious. I'm going to go call the medics right now, you just stay put." Martha pleaded, gently removing the girl's inappropriate hand. "Glen Honey??? WILL YOU COME UP AND SIT WITH KASSY, SHE ISN'T WELL AND I'M GOING TO CALL THE AMBULANCE!" Martha called out as she jumped up from the bed and bolted from the room.

Kassy's hand now cast from her mother seemed bored and without purpose, especially when she had another hole that yearned for attention. She pulled it back under the covers and slipped it too between her legs. While her left hand worked furiously at her pussy, rubbing her G spot and causing her to cum over and over again, the spill over ran down and lubed her naughty asshole. Her right hand felt right at home as it spread her ass cheeks and wriggled its way up tease her bung. First just the tip of a finger slid in and then the whole finger. She could feel the other digits inside herself through the wall between the two orifices. Kassy came hard, her pussy exploding with her own girl cum, she suddenly found out that she was apparently a 'squirter' as the mattress below her dampened and soaked with her juices.

"AAAWWWWWWWW!" Kassy screamed out in ecstasy just as her worried father entered the room.

"OH GOD, my poor baby girl!" Glen shouted with worry as he rushed to the bed, seeing his daughter writhing in apparent pain. He sat down on the bed but immediately jumped up feeling the wet mattress and thinking she must have wet the bed. "MARTHA YOU'D BETTER TELL THEM TO HURRY!" Glen shouted back down the stairs.

All Glen could think about was Kassy's earlier revelation that she'd gotten into her brother's chemistry project. Could the state of his sweet innocent, apple-of-his-eye daughter now be because his own son had carelessly brought some dangerous drug into his house? Dear God he hoped it was something less nefarious.

"Kass, hun...you just try to stay calm, Your mother is calling the medics right now." Glen pleaded as he knelt beside his daughter's sullied bed, hands clasp in prayer. "You'll be alright...you're gonna be fine...It's ok..." He chanted like a mantra, trying to will it into existence.

Kassy suddenly sprung up, the sheet falling away and her new form revealed, Glenn reeled in horror seeing his tiny daughter's new swollen naked body. "DEAR GOD! What has he done to you?" Glen cried out.

Kassy wrenched her hand free from her pussy and reached out and grabbed her father's prone head by his greying hair. She pulled him forward and slammed his surprise stricken face into her sopping snatch. "OOOH DADDY EAT IT!" Kassy called out as her head bucked back feeling his bearded face against her throbbing clit.

Glen pulled himself free, completely awe struck, his face now smeared with his daughter's juices. "NO KASSY!" He protested with a gasp.

It was then that Martha's voice came hollaring up the stairs. "Good news Glen, 911 said that they had a unit in the area, they'll be here any sec..." Martha started to say but when she entered the room and saw her daughter's massive tits and her hand rapped around her husband's head, she gasp with horror. "...OH MY GOD, GLEN WHAT ARE YOU DOING?"

"It's not me, she's crazy honey!" Glen pleaded, wrenching her hand free of his head, still tasting her juice on his lips.

"Well don't just sit there wrap her up with a sheet...subdue her!" Martha commanded and her husband obliged her. He pushed his daughter down and tightly wrapped her in the wet sheet. It was just then the urgent knock of the paramedics came from downstairs.

"Glen you carry her down and I'll leave a note for Kevin!" Martha said, completely distraught with worry.

When Kevin finally returned from his extensive shopping trip, he'd been in such a hurry that he'd barely noticed that his father's car was gone from the driveway. He'd run upstairs and found Kassy's room empty, with the only clue being a hastily written note on Kassy's nightstand.

' Kev, Had to take Kass to the ER. She's gotten much worse. Meet us there! ' The note read, and at the bottom. ' PS WE NEED TO TALK! '.
 
"Where the hell is everyone?" Kevin thought. Walking around the house and not finding anyone. Kassy's room was empty. After a few moments of searching, the note finally caught his eye. Reading it quickly, he realized the worst had probably happened. Her sexual desires had gotten the better of her and she'd seduced their father.

"Oh shit!" he practically yelled. Rushing back down to his mom's car and throwing the bags back in. Starting up and speeding off to the hospital in a fury. Rushing to get there as fast as the car and the speed limit would allow. If Kassy was let loose, god knows what might happen. It was up to Kevin to lock her away for a bit until he could find some way to manage her new lust.

Parking hastily in the lot, he ran into the room. "I need to see a Kassy Kent!" he hurriedly said to the front desk. "I'm her brother Kevin. She was brought here a bit ago." As soon as he figured out her room, Kevin bolted.

"If Kassy is like the rats, she's going to demand dick from anyone. Until she's bred. I need to get her out of here." He mumbled to himself. Rushing to her room and throwing the door open.

"Kass, come on now!" he yelled.
 
Glen and Martha had been waiting out in the lounge after Kassy had been admitted for an apparent allergic reaction to an unknown contagion. Martha was terribly worried while Glen seemed oddly distracted. Their father was looking through the vending machine while their mother was nervously paging through a magazine when Kevin rushed by them and neither of the worried parents seemed to notice him.

Meanwhile Kassy had been emitted to the ER, with the triage nurse unable to easily diagnose her strange symptoms. They'd stripped away the soiled sheet she'd been covered in and dressed her in a hospital gown, but not without quite a bit of struggle as Kassy couldn't seem so keep her hands out of her own snatch. Eventually the Orderlies had to actually strap her down to the gurney so that the doctor could start his examination. Much of his questioning revolved around what sort of drugs she may have ingested, as many young people often took illegal substances and omitted the fact to their parents.

"Ecstasy? DMT? Ketamine? Amphetamine...Meth?" The doctor asked as Kassy writhed like a chained animal on the bed.

"Noooo.....No drugs, I'm just horny....PLeaseeee FUCK ME!" Kassy pleaded, flicking her tongue like a snake at the white coated doctor.

"Miss...It's important that you answer honestly so that we can offer you proper treatment, your parents are very worried." He said in an uninterested clinical tone. Meanwhile the large black orderly in the corner couldn't seem to keep his mind from fixating on blonde bimbo, holding his hands over his crotch trying to shield the fact that he had the start of an erection brewing.

It was then that the door burst open and Kevin rushed in, carrying his bag of goodies. "Kass come on NOW!" He'd yelled, drawing both the attention of the Doctor and the big black Orderly.

"Excuse me sir, but you aren't allowed to be in here!" The doctor said sternly.

"KEVY!!! GET ME OUT OF HERE! I NEED COCK AND I NEED IT NOW!" Kassy exclaimed happily.
 
You must log in or register to reply here.
Back
Top Bottom