Kinda basic plots (would also be game to turn any of these into something more long-term):

-(A) catches (B) on OF or something and confronts them about it

-One is the boss, the other is the employee that isn't that good

-One of us is the pizza guy, mechanic or repair man, and the other person is gonna pay without money.

-We are teenagers trying to be quite so the adults don't hear us.

-The royal servant walks in on the prince being fucked by a knight; the knight leaves the prince to the servant's mercy

-(A) is throwing a party at their house and the other is their friend, they get drunk and horny and go upstairs

-A lustful Adventurer travels to "tame or be tamed" by mythical beast

-(A) catches (B) being used by a ghost, and lays a trap to catch the ghost

-Everyone knows the priest offers more than just confessions to all the lonely people in town, married or not

More put together kind of plots

-A lonely boy in college (A) summons a demon (B), (the demon could be a sex demon who demands sex for payment, or some other demon with some other payment), after a while the demon and the human slowly start to fall for each other.

-(A) is a bad kid from school who has had sex with every single member of every sport team, (B) is the only member they have not and when (A) tries to seduce them, (B) falls for them and tries to make (A) love them to.

-(A) is a teacher who is openly gay, and before school starts he goes to the gay club. (B) is his student who is going to a gay club and they both get drunk and head back to the teachers place. (They can either pass out or not and do that nasty) and the continue to see each other without ever finding out till school starts.

-(A) is a person full of emotion who is in love (or just interested) with (B), (B) is someone who shows no emotion, and but when they start to hang out, they slowly starts showing them (not like, they put a wall up, think like medical condition not showing emotions)

-It had been no secret that once (A) started their second year in college that money had become increasingly tight. Having to make the decisions on what to prioritize and having hours cut back at work certainly didn't help either. (A) was the type that refused to ask others for money, insisting they’d be able to handle and that things would turn around. After a few months, it seemed like things were indeed starting to improve where (A) was stressing out less about money, just simply stating that they had gotten a second job and had switched to online classes and never really giving more details than that. The secret was that the second job (A) had just miraculously found was actually doing sex work. It paid well enough and after the first couple weeks (A) had actually kind of started to enjoy it, finding it thrilling. Everything had been going well until one night everything seemed to come crashing when going to meet a client and saw (B)

-In a cyberpunk / dystopian setting, (A) and (B) have either signed up for or been forced into a breeding program, possibly having to show up to a lab or some such to do the deed. Romance optional, reproducing required, other obligations be damned.

-In medieval fantasy, for political relations, (A) is assigned as an apprentice to (B) - a renowned warrior. (A) is under heavy pressure to learn well, while (B) is begrudging at best. Privately, (B) demands full use of (A)'s body if they're going to make the effort to teach.

-(A) has settled into a healthy, comfortable, and admittedly dull relationship. (B) is a more exciting alternative who isn't afraid of doing some homewrecking.

More about me:

-My name is Ben and I’m a 28 year old trans guy.

-I can write characters of any gender (though currently would prefer to be playing a trans male or nonbinary person)

-I’d prefer my partner to be 21 but so long as your 18 that’s all good

-Happy to discuss kinks/limits in messages