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Sister...? (Yummyfuta x Blazorna)

Y

Yummyfuta

Star
Joined
Jan 5, 2018
Natalie sighed as she made her way through the dwindling crowd of students in the school hallway. Whilst the crowd was all heading towards the exit in order to head home after another long schoolday Natalie was walking against the flow to head for one of the science classrooms. Her sister, who was supposed to be walking home with her, had instead gone off to work on some personal project yet again, completely forgetting about any other plans. This wasn't the first time this had happened either, at least twice a week her sister would seem to be suddenly struck by inspiration and scurry off to a mostly unused classroom to work on something, though would never tell Natalie what it was or why she was doing it, though Natalie simply assumed it was for extra credit. Not that her sister needed it, she was something of a genius after all.

"Ok sis" Natalie sighed as she got the classroom, shaking her head. The window had been blocked up as usual, her sister didn't want anybody passing by to see what she was working on. There wasn't much worry about people sneaking into the classroom at least, her sister had a reputation for being a little weird and anybody that didn't know her knew to just stay away. "Hey, sis" Natalie knocked on the door, before opening it and stepping into the classroom, glancing around. "Don't worry it's only me. You in here sis? You realise school is finished for the day and it's time to go home right?"
 
"Really? And I am just about to do an experiment." a voice said in mild annoyance from in the back.

A girl with the same wine red red hair as Natalie, although in a ponytail was standing over a centrifuge as it was in use. Opposed to her sister, she had a considerably smaller bust. She had been wearing the school uniform with a labcoat over it. Compared to her sister, she was smarter, but nowhere near as attractive towards the guys. This wasn't much of a concern for her as men didn't attract her attention, opposed to her sister. For the longest time, she was drawn to her own sister, but kept quiet.

"What brings you here, sis?" Janice asked as she turned off the machine and turned to her sister, taking a moment to look over her siste, focusing on her breasts for a moment. She thought for a moment before she grinned. "Perhaps if you help me, I can finish up and head home. Think you can help me with this experiment?"
 
"You're always just about to do an experiment Janice" Natalie rolled her eyes slightly, glancing around the room, looking through various pieces of equipment that were set up to eventually find her sister standing near the back. "There you are..." She sighed softly, closing the door behind her and making her way through the classroom carefully. "Come on Janice, what do you think brings me here? School is done for the day, it's time to go home" She folded her arms beneath her chest, pushing it up slightly which only ended up pulling her sweater a little tighter.

"Hm? Help you? Well....alright, I'll do what I can" Whilst Natalie wasn't on the same level as her sister when it came to intellect she was certainly no slouch, still one of the top students in the school. "So what exactly can I do to help out anyway? I've no idea just what it is you're even working on here" Natalie adjusted her glasses and glanced around at the various pieces of equipment set up, centrifuge running and multiple chemicals flowing around.
 
Janice smiled a little upon hearing her sister agreeing to help. She went and opened the centrifuge before pulling out a test tube filled with a blue liquid. She went over and poured the liquid into a beaker full of a clear liquid, the mixture becoming green as a result. The genius then went and poured the concoction onto her own hand and rubbed it in before approaching her sister.

"I always admired how lovely you looked, always the envy of girls and attract so many men with your figure. It's envious to be honest." she admitted. "And for this experiment to work, I need someone so attractive for accurate results."

She wasn't used to flirting, and wanted to seduce her sister, due to the liquid increasing her lust steadily, The genius slowly closed the door and locked it before she spoke up again while looking Natalie in the eyes.

"We have a good baseline now, I would like you to undress a little so we can guage how I react." she said with a straight face. "And do not worry, I have no intentions of humiliating you.You are my sister after all." She spoke with honest truth, no wanting her to have any ill schemes.
 
"Whew...is it getting warm in here? Must be all these chemicals and bunsen burners..." Natalie fanned herself with her hand as Janice put the strange fluid onto her hand, feeling her cheeks flushing a little as a slightly odd scent filled her nostrils, though given the amount of chemicals all around the room she wasn't surprised by a strange smell or two. "Hm? Wait, sis did you say you wanted me to undress?" Natalie blinked a few times as her mind tried to process the request, though her mind was also becoming increasingly hazed for some reason. "I...well just why do you want me to undress anyway?" Despite that Natalie was already removing her sweater vest, though she was assuming that Janice didn't mean undress all the way, just...take a few items off that wouldn't raise any eyebrows.
 
"I want to see how visual stimulation will affect me. And you undressing gradually will be the best way possible." Janice explained before she gently stroked her sister's cheek. She sat down on the counter and crossed her legs as she watched her sister. "I locked the door as to avoid you becoming embarrassed. Feel free to remove as much as you would like. It is just us sisters here."

She felt her liquids effect take effect, stimulating her body in various ways. She ifdgeted slightly as she started to feel uneasy, but wasn't painful. She kept her attention on her sister regardless, intending to see how far she can go.
 
"Just how exactly are you expecting that kind of 'visual stimulation' to effect you anyway...?" Natalie raised an eyebrow, not able to figure out what her sister was thinking. She couldn't help but shiver as Janice stroked her cheek though, and the scent got even stronger, clouding Natalie's mind even further. Well, at least the door was locked so there was no worry about someone else coming in right?
Natalie continued to remove her sweater vest, though as she pulled it up past her chest it caused her breasts to bounce around, their size meaning even the bra Natalie was wearing couldn't keep them entirely steady under that much pull.

"Um....ok so..." Natalie dropped the sweater to the floor beside her, then tugged out the bow around her collar. She stood and fidgeted for a moment, thinking about how to proceed, before next removing her shoes and socks with a few quick movements of her feet. She considered stopping there but....well Janice had said 'stimulation' right? And standing there still basically fully dressed probably wasn't very stimulating. And besides, it wasn't like Janice hadn't seen her naked before already right? After another moment of hesitation, Natalie reached up, starting to unbutton her blouse, gradually revealing her plentiful cleavage.
 
Janice fidgeted a little more as she smiled while her sister began unbuttoning her blouse. She felt her body starting to feel different, signs that her experiment was working. She leaned forward and gave her sister a quick peck on her cheek.

"So far so good." she said while stroking Natalie's cheek again. Her desires began to surface strongly, but it took every ounce of her will to not kiss her immediately. She had to bide her time to wait until her sister was fully compliant to do the second stage of her experiment. She kissed her sister's neck a little to tease her before leaning back, enjoying the sight of her sister undressing.

"Feel free to do anything you want. Stimulate me the best you can." the girl said, encouraging her sister to be more bold.
 
Natalie blinked as her sister kissed her cheek, though at least that wasn't too unusual. When Janice kissed her neck though, she shivered slightly, her expression just a little confused. "Uhh....Janice...just what is it you want me to do here...? This is getting just a little bit weird even for you sis..." She hesitated at having her blouse half unbuttoned, before sighing and continuing, eventually unfastening it completely and slowly dropping the garment to the floor behind her, revealing her bra and cleavage entirely. After hesitating for a few more moments Natalie reached down, unzipping her skirt and then just letting go, allowing it to drop and pool around her ankles.

Natalie now stood there infront of her sister in just her underwear "Ok so um....what should I do now? You don't really want me to take my underwear off too do you?"
 
"As I said, to stimulate me. It is to see if this will function properly." Janice explained as she got to her feet and began to disrobe herself. One by one, she stripped down, until she herself was in her underwear as well. revealing a buldge in her panties, a sign of what wasn't normally on a female present. "I have been working on a medicine that naturally balances one's genetics to become both genders. And you, being the envy of many girls and the attention of so many men, were the perfect person to help with this. Even if we are related, stimulation is still effective if you're attractive." a blush formed on her face as her own mind began to become foggy. "I hope you don't think weird of me... You're the only one I could trust with this."

She averted her gaze, debating if she should confess her feelings or not.
 
"See if what will function properly?" Natalie blinked, then shook her head as Janice began to undress as well. "Oh geez, Janice just what are you doing? Why are we doing thi-" Natalie cut off as she saw Janice's panties, just staring at the bulge that most definitely hadn't been there before. "Uhhh...wait...I...what...what is that....?" She raised a hand to point at Janice's crotch. "Eh? Wait...become both....wait wait wait....are you telling me that thing is a...a....penis?!" Natalie looked up at Janice with an expression of disbelief. "C-come on Janice that's impossible. I don't care how smart you are there's no way you've created some kind of drug that lets you just suddenly grow a penis all of a sudden!"
 
"I spent months to become like this." she said before biting the bullet. "I made myself like this for you... I wanted to give you a reason to be with me. I don't like boys. For the longest time, my eyes have always been on just one person. I never said any of this before because I'd be rejected, for being a girl, let alone being your sister. I love you Natalie. More than I should as your sister... I changed myself so you could see me as someone that isn't a girl. I loved you for the longest time, and I want you all to myself. I am scared of losing you to a boy. If it's because I was lacking what they had, I couldn't stand that thought. That was led me to do this."

She wrapped her arms around her sister and gave her a desperate kiss as tears started to run down her cheeks. She allowed her emotion to take over, bracing herself for the worst.
 
Natalie was caught off guard by the sudden confession, she had no idea how to really react to that, what could she even say? Sure she'd had people confess to her before, but almost always guys. Yeah there had been one or two girls as well but....but this was her sister! Natalie had turned all of them down of course, she'd never had any real interest in any of them, they were all so plain, so boring, so....normal, and that just never did it for her. This though....well...this was most certainly anything but normal that was for sure. "Uhh...Janice? I-" Natalie was cut off as her sister suddenly kissed her, though it meant her mouth was already open when Janice kissed her, granting the girl easy access to her sisters mouth.

"I...I uh..." She panted a few times when the kiss was broken. Was this really how Janice felt? Or was it some side effect of whatever she had done to herself? "Uh...well...I um...why don't you....at least finish undressing so I can see this new body of yours and we can uh....go from there?" She grinned sheepishly.
 
Janice wiped her tears away and smiled before she obliged, pulling down her panties , revealing a semi erect member, its size only half way revealed. It was obviously meant to be larger than average, but not overwhelming. she went up to her sister and kissed her on the cheek.

She then reached out and undid her own bra before she spoke up, now fully nude."You strip nude too, my dear sister. I'm not going to be the only one who is naked." She wrapped her arms around Natalie's neck lovingly. She reached back and ran her fingers against the bra straps, but didn't do anything else. She wanted her to strip herself naked. "So, how is it? I got this for you alone, Natalie."
 
Natalie looked down as her sister removed her panties, eyes going wide as she saw the cock, so it really was...well...real. And it was big...definitely bigger than usual from what Natalie knew. "Uhh...oh wow...that's...that's real isn't it? That's a real...." Natalie swallowed nervously, glancing up to Janice's face, then back to the cock. "Uhh...oh um...right...I...ok I'll...strip too...." Natalie wasn't quite sure why she agreed to that, she still felt rather unusual, like something was affecting her mind without her realising it.

After hesitating for a moment, Natalie slowly reached around, undoing her bra and then slowly tugging it away, revealing her large breasts which despite their size didn't sink even slightly, not only were they huge but they were incredibly perky too.
 
The member bcame fully erect once Natalie removed the last of her clothes, becoming a ful eight inches in length and an inch and a half for the girth. As both sisters were nude now, Janice went up and wrapped her arms around her sister's waist and kissed her deeply, driven by an impulsive urge to show her sister how she felt once again. Her member poked against her sister's inner thigh sightly, being careful not to penetrate her core despite her desire to do so.

" You are beautiful, sister. more so than you're wearing clothes." she said after breaking the kiss. She rubbed her arms up and down Natalie's back slowly as a sign of affection. She gave Natalie a warm smile, happy she hasn't been rejected.
 
"Oh my" Natalie blinked and stared down as her sisters new cock became fully hard. Out of curiosity Natalie couldn't help but reach down, poking at it gently to check if it was really real, at least until Janice kissed her anyway, Natalie being caught off guard, shivering which caused her thighs to rub against the cock further. "Uh...th-thanks..." The kiss only seemed to have increased the effects of whatever substance Janice had exposed Natalie to, and with the position of the cock Janice would be able to feel the heat and moisture between Natalie's legs that was rather rapidly increasing.
 
Janice slowly rubbed her member against her sister's core, resisting the urge to claim her immediately. She kissed Natalie again, this time pulling her sister against her own body. She broke the kiss and brought her lips to Natalie's ear to whisper sensually in it.

"Will you let me claim you as mine? Let this cock that was created for you give you pleasure only I can give you? I want you so badly, it hurts. " she said, almost whimpering at the end. Her mind was being consumed by the thought of not only having Natalie to herself, but to have her way with her. A thought that was increasingly enticing with every passing second. She barely could hold herself back, and if it became too unbearable, she will claim her sister no matter what.
 
"I..." Natalie shivered as Janice's cock continued to rub against her, Natalie's pussy growing hotter and wetter in response, far more than should be expected thanks to whatever substance her sister had exposed her to. Normally such a request would probably make Natalie refuse to go any further, even for her darling sister, but her body was starting to burn so hot that rational thought wasn't exactly high up on her list of priorities. "I....y-yes....yes you can..." Natalie panted out the words before even realising it, her body was craving it so badly right now, she couldn't possibly refuse when such a cock was being offered to her so freely.
 
Janice smiled and kissed her sister deeply before she slowly guided her to bend over before getting behind her. The genius slowly slide her member into her sister's folds, moaning softly as she realized the member was more sensitive than expected. She bent over to gently press her body against Natalie's, her hands moving to begin fondling her sister's breasts slowly. Her lips went towards the neck and gently kissed her there before giving a slow, gentle thrust to allow Natalie to grow accustomed to the cock.
 
Natalie swallowed nervously as she was bent over one of the lab workbenches, several chemicals bubbling away right infront of her face, more all around the pair of them. "A-ah!" Natalie's eyes went wide as she felt her sister start to slide her cock inside, grunting and clenching her fists as it slowly sank deeper and deeper. It seemed that Natalie's body was already plenty wet, far wetter than normal arousal would normally cause, whatever Janice had done to her had certainly pushed Natalie's arousal to almost inhuman levels. She groaned as she felt her sister begin to fondle her hanging breasts, nipples as large and hard as bullets, then squeaked as Janice thrust inside of her. "O-oooh...oh god...."
 
Janice began to pick up speed gradually as she began thrusting more into her sister, enjoying how she felt as she moved in and out of her. Her fingers kneaded the round mounds while gently pinching the nipples teasingly on occasion to stimulate Natalie. Her lips parted and gently nibbled on her ear lobe,

"Oh sister, you fit so perfectly on my nice, hard dick." she said as she moved deeper into her sister, enjoying her immensely. "Oh god, I want you all to myself, make you mine. You are so good to be inside. I can't get enough of you. " Her lust began to become more prominent, wanting to make Natalie all hers completely,
 
"Ah...ah..!" Natalie moaned as her sister began to thrust into her harder, her breasts becoming more and more sensitive, then squealing in pleasure as Janice pinched her nipples, each one feeling as sensitive as a clitoris now. "Nnnngh....m-more....p-please...please Janice....more! F-faster...harder!" Natalie moaned loudly, her hips thrusting back into her sisters own thrusts. Lust and pleasure were overtaking Natalie's mind, another side effect of whatever Janice had exposed her to. Natalie's grip on the workbench infront of her tightened, her knuckles turning white, the various vials of chemicals being shaken and stirred in ways they weren't intended to be in Janice's original experiments, though Natalie neither noticed nor particularly cared about that right now.
 
Janice obliged and thrusted faster and deeper into her sister like she asked. She wanted Natalie to be hers alone, to love and have her way with. She gently pinched the nipples more before moving her hands forward, puttiing them on the table as she applied more force going into her sister. a vial of blue liquid fell over and splashed onto genius's hand, soaking into her skin. Seeing what it was, Janice didn't worry, knowing that it was saf and not toxic.

However the exposure did have an effect on her. It wasn't noticed, but the genius's thoughts towards her sister became filled with seing Janice as something belonging to her that needed to be bred before someone else did,

"You're mine, sister, I won't give you up." she moaned out possessively as she thrusted as deep as possible into her sister, staking her claim over her.
 
Natalie didn't notice the liquid that spilled onto her sisters hand, her eyes were closed as pleasure washed over her body again and again, every thrust driving her to new heights of pleasure. Her nipples were as hard as bullets in Janice's hands, almost like truly pinching at steel. As Janice started to thrust even harder and deeper though, more containers of chemicals began to shake all around the girls, though once again Natalie neither noticed, nor would she have particularly cared even if she had. Her body tightened up even further around Janice's cock upon hearing that her sister wouldn't give her up, her juices flowing even more freely. "O-oh god...oh god Janice...I...I think...I think I'm gonna....j-just...just a little more!"
 
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