Well, some of the kinks I don't like have already been mentioned but here I go.
Harems/Reverse Harems: I will say something a woman doesn't expect to hear from a man "I don't ser myself fucking on a daily basis with more than one girl". I don't like when people regardless of their gender want a lot of other people to have sex with and have a sexual party only for themselves. I don't like it. Too many guys or girls fucking with only one "chosen one" nah, not my thing.
Gangbangs: This was a really frequent kink ammong girls on reddit. I don't know about many people but I don't see myself fucking a girl with someone else, or fucking a girl someone else has just fucked a while ago. In my country we call that chicha steering...yeah I don't consider that very hygienic, it honestly grosses me out more than scat. If you like it, fine. But don't force it on me.
Cucking: This is almost the most frequent thing I warn I am not into and still i get people asking "Are you okay with a cuckhold rp?" No. Read my post, I am not! I am not comfortable with anyone watching me while I fuck someone nor watching a couple fucking, even less if that person is someone significant to my, from a loving sister or a friend to a girlfriend. Why would I like to watch them being fucked? No way! And I would find creepy having a random person watching me fuck my gf, that's for sure.
Cheating scenarios: I really, really dislike them. They are a major turn off. These plots are like "I am married with an asshole but for any reason I don't leave him. I want you to fuck me" but some go even further and pretend to ruin a seemingly perfect relationship just for the sakes of your selfish personality. I don't mind what gender my partner is, cheating is just wrong. And there is people that is so shameless about cheating scenarios that they try to convince you with poor arguments such as "It is not cheating if nobody knows" or "It is not cheating if everyone knows". No, simply no, I have characters that are different from each other but they agree with me, they won't wreck a relatiinship for any reason.
People that says having a male feral animal fucking your holes is acceptable bestiality while a consenting feral female is not: When we come down to roleplay this is also something more or less normal, I even have done so "bestiality" scenarios with TALKING animals, most of them dragonesses and pokemon (as I really like the bond a rider and a dragon can acquire and pokemon can get a bond with their master no person could match). Yeah I know I will get judged here but it is only on roleplay roleplay. Anyway, just as the cathegory says; I find it a bit hypocritical when people are into bestiality, and even want you to play a whole bestiary of existent and non-existent creatures, when you ask them to do something similar for you they refuse and say it is not acceptable. My reaction is "Ok, you like bestiality when it is om your favor, but when it is on someone's else it changes completely and it is taboo, right?"
Rape/Non-con: As many. I cannot roleplay something in which one part doesn't want sex and fucking a girl until she loves you? Yeah, not realistic and not enjoyable.
Blackmail: Not to kinkshame anyone but I find lazy to base an scenario around blackmailing. The whole concept of theatening someone to give away sensitive information to have them as their sexual slave makes me think there isn't much plot aside sex
Plots based solely around sex: Yeah, there may be a lot of people into just the "fun part" but I don't find it amusing when the whole roleplay is just focused on sex. I mean there are more things to do "together".
When someone takes their freedom to tell you exactly the chsracter you are going to play: I have a decent variety of characters, different personalities, heights, body builds and interests. I don't find it amusing to roleplay with someone's else character. For example "Your character will be the muscly and popular quarter back on his highschool team. He is irresponsible and likes to drink a lot" eeeeeh, no! Let me decide who will I roleplay as. How am I supposed to roleplay a quarterback when I don't know about football? *kicks the ball and scores* is all I could write, I don't know.
People strictly into hypercocks: Let's be honest, size matters and I know that, the pleassure a big meaty rod can give you is not the same a tiny wiener will attempt to give you. I get it, but have you really had a REALLY big cock inside you? Yeah I don't find unrealisticaly big dicks a thing I enjoy. Specialy when on their own fantasies my bigger character (down there) is considered small. Alright so a 18.5 centimeterd cock is small, ok...
I mean I would get it if we are playing as characters with a completely different size, for example if my partner is playing a giantess I'd understand...but a 1.60 meters tall girl? A two feet long cock will definitely break you...
The cock standard on furry fandom: I love furries or anthro characters, but I just hate the standards. A normal sized cock is considered micro, a big cock irl is small. You must be at least 30 centimeters down there for people to say you have a big cock in said fandom. No thank you, so much blood down there will surely make me faint or have heart insufficiency.
Extremely vanilla people: not so common but it is really boring. Only vaginal sex on the missionary pose? Yeah, not my stuff
Doormat submissives: There is just not much to do with them
Having to play a despicable character: Some people is into this and they tell you to play an excessively dominant guy who would beat the shit out of their characters, rape them, abuse them, treat them like garbage...nah. I am a very romantic and caring person, I don't want to harm my partner. Perhaps some light bdsm here and there, but nothing too harsh.
Tentacles: never understood the hype about them
School roleplays: I am already in college, having to study. Why would I study with my character?
Overly sexual female characters: I would understand an insatiable sex drive if you are playing a dragoness or any beast im general in heat. But if your character is constantly craving sex every 5 minutes it can be any race but will make me feel sorry about them.
Girls with excessively big tits: Yeah, I have friends and I know having such big tits can give you back pain...LOTS of it. I find it lacking of aesthetic when your boobs look bigger than they should be.
And the list goes on X3