Right now I only have time to post one story idea, one I have been wanting to write for some time. I will eventually include lots of ideas. Here is the one for now-
I would play a 32-year old or so mother, who has been raising a son or daughter by herself. The son or daughter(aged 16-18) is generally well-behaved, but sometimes he or she acts out to get his/her mother's attention. Well finally the mother has had enough, and decides to employ some gold old corporal punishment. However, during the punishment act, unintended and unanticipated sparks of romance start to flew between the two of them. And then, against both of their better judgment, they decide to stoke the fires of their new sexual attraction to each other and see how far they can take it. The punishment scene, itself, could be a one-off, just there to be the point of departure to spark the romance, or the mother could continue to "punish" her son/daughter if they decide they actually enjoy it.
Another incest idea-
My character is a 17 year old girl, almost done with high school but she has no idea what she is going to do with herself afterwards. Your character is her slightly older brother, who has been away to college for the last few years. The younger sister has always been socially awkward, more of an artist and a dreamer. She is fairly pretty, though, and could still have her pick of boyfriends, however she is still a virgin. She has been saving herself for her brother, even though she knows it is just a fantasy that could never happen. Or so she thought, before her brother comes back home on spring vacation and works up the courage to tell his sister than he has been holding in sexual feelings for her as well.
One more idea for now-
Dawn(my character) has been very sick all her life. She has spent the majority of her life between hospital beds and her own bedroom, when she was even well enough to go home. Her parents have tried everything and nothing seems to make her well enough to where she can leave her room. Then they meet a doctor who lays on them a controversial theory- the reason no medicine has been able to cure their daughter is because her illness is all in her mind! She hasn't been making herself sick on purpose, of course, the symptoms and her overall frailty have been real enough. But she doesn't need medicine, says the doctor, she needs romance and sexual attention.