Let's have some sexy fun!

Hey there! I'm new to the site but not to roleplaying. I'm open to either short or long-term RPs, and I'd like a significant amount of smut but a fair bit of plot is welcome too (especially for longer-term plays). I'm also happy to consider modifying any of my ideas, so if something sounds like it would be great if only you could change a piece of it, let me know!

Pairings
Brother/sister
Father/daughter
Professor/ College student (I can play either)
Boss/employee (I can play either)
Father/son's girlfriend
Boyfriend/girlfriend's sister
Father/babysitter
Son's friend/friend's mother
King (or other authority figure)/manipulative witch

Plots
(Unless the plot description specifies characters, any pairing above can be used with any plot.)
Blackmail

YC blackmails MC into sex, either with real or faked evidence of some kind of wrongdoing. If we're looking for something long-term, she can start with fairly mild activities and demand more as we go along. At first he believes it's a one-time thing so he goes along, but when she reveals that she's not going to stop making demands, he decides to turn the tables. He secretly videotapes them together and makes sure it's clear on the recording that she's forcing this on him. But the sex is amazing and he's suddenly not sure he wants it to stop. When he confronts her, she realizes his conflict and pretends not to believe the tape exists, insisting they watch it to prove he caught her. Between watching how much they both enjoyed it and her coming on to him, he gives in and the blackmail is no longer necessary.

Drugged

YC has tried flirting, wearing sexy clothes, even outright asking for sex, but MC always refuses. Now, YC has gotten her hands on an extremely powerful aphrodisiac, and she's finally going to get her way. She arranges for them to be alone when it takes its full effect on him, and now she'll finally have the night full of pleasure she's been waiting for. We can discuss exactly what the drug does (e.g. maybe it keeps him attracted to her after they've had sex, or something like that if we want it to be long-term).

I have a fairly well fleshed-out idea of the first few scenes of this one, which I'd love to use if you're interested--ask if you want to know more. I created it for this as a father/daughter pairing, but it could work pretty well with any pairing.

This one could also be done in reverse, with MC drugging YC instead.

Magic

MC is a seemingly ordinary man with the potential to be a powerful magic user, but he has no idea about that. YC is a witch with aspirations of power, but she needs to either eliminate MC or get him on her side to hope to achieve her goals. Her power feeds on sex, so she uses her powers to seduce him and/or cause other women around him to do so, hoping to draw power from it and keep him distracted so he won't learn the truth.

If we want this one to go long-term, there's plenty of room for plot. MC eventually learns of his potential, but can he find a way to defeat the witch or will he be overcome by the pleasures she offers?

Medieval magic

MC is the king of a powerful nation. YC is a secretive and powerful witch (optionally she could also be MC's long-lost daughter or sister--he wouldn't know this, but she would). She uses her magical powers to seduce the king and manipulate him into giving her more and more influence over things, all the while using sex to strengthen the magic and maintain her hold on him. If we want this to go long-term, others close to the king could become suspicious and try to break her hold, which weakens the longer they go without sex, and she would have to fight to keep control.

The Succubus

MC is visiting his girlfriend's family on a break from college. While exploring their house, he stumbles on a dusty old book and reads some strange words written in it. This casts part of the spell that summons a succubus. He stops short of allowing her to manifest herself physically, so she needs to gather power by getting him to have as much sex as possible before he leaves. She possesses the girlfriend, her mother, her sister, and any other women she can find, using them to keep him busy and distracted from figuring out how to banish her.

The Queen's Predicament
 

YC is smart, young, and stunningly beautiful--which made her the perfect trophy wife for an old, ugly, and tyrannical king. She would like nothing better than to be rid of him, but she's no killer, and even if she were her situation would be dangerous. They have no children, so there's no way to know who would take the throne or what he would do to her. But if she could form an alliance with someone, perhaps the king's bastard son or a well-respected knight who might have a claim to the throne, she'd be in a much stronger position. Or perhaps the king's court wizard has thoughts of using his magic to seduce the queen and take the throne for himself?

Babysitter/father

YC has wanted her employer ever since she first met him. She's tried wearing somewhat revealing clothing when she knows he'll be home before his wife, maybe a little flirting that doesn't step too far over the line, but she's had no success. Then one night, he gets home just as a storm hits. His wife will be delayed at work and everyone in the house has to hide in the basement--the perfect opportunity for YC to turn on the sex appeal and convince MC to take her mind off her fear of the storm.

A Secret Past

This one ideally would involve you playing two girls (or playing it out with three people), but could probably work without that if you love the story but don't want to play two characters.

MC has a twin sister (TS) and a younger one (LS). (Ages can be worked out, but everyone will be old enough to comply with site rules if/when they take part in sex). When the twins were in high school, they were both dumped the day of the homecoming dance. They told their parents they were going to the dance anyway, but instead they went out, got drunk together, and ended up having sex in the back seat of MC's car. The sex was incredible and they decided to continue. All three kids shared a bedroom, so it was easy enough for TS to sneak into MC's bed after everyone was asleep, throw the covers over them, and have some fun as long as they kept quiet.

When they graduated and went to different colleges, they agreed to put this behind them. It was fun, but no one could ever know. Now MC is back for the summer after his first year of college. To this day he's sure no one else knows, but he's wrong. It turns out LS woke up one night and saw some of what was happening. Once she thought she was old enough she asked TS to let her have a turn, but she refused, saying LS was too young for this. But they worked out a compromise: TS would occasionally leave the covers off so LS could watch, even though she wanted to do more. TS promised that she'd let LS have her turn when she was old enough.

I imagine this one leading to ongoing secret threesomes, but there are lots of ways it could get there, or it could go a different direction entirely. I'll put up some possibilities at some point, but if you like the idea and have something in mind, let me know!