I have enough stories, but here's an idea that someone else may want to run with: A woman finds herself transforming every night into someone else's dream sex toy. One night she's a curvy, hot blooded Latina, the next night she's dressed like teenage jail bait, the next night, she has a huge ass and craves spankings and anal, then a geisha girl, and every night she knows what's happening but can't stop herself or keep from getting turned on. It could be a woman who moves into a new apartment building or gets a job at a business that does STEM research.
You could make her a genie of sorts but I think I saw a story where a girl basically falls into other people's dreams so that may be the easier plot device.
Or -because I have this thing about succubi and keep mentioning them- the main character could be a classic succubus who feeds on people by appearing to them in their dream as the lover that they are dreaming about. Granted that this is only if you want the main character to be a succubus. Or if she doesn't know that she somehow inherited succubus blood and this is caused by her powers starting to awaken.
