When i think about it, it comes down to "why not?"
In a porn game, if there is a sexy character that is not fuckable you remember that and ask "but why?" especially when 90% of characters are fuckable, you meet that 1 you cant and you say "why not?"
You have to remember everything is "sexy" to someone, so in turn every character will have a fan and they will want to fuck them. wether it be there eyebrows, hair color, job, stance(pose), chat(speach) or anything else. "teasing" is a good word to remember here XD
You could have allot of fun with ways to "fit this in" to your lore/story.
Dreams are good, you can do almost anything with that. But i like the idea of a "secret" mode or story change of sorts, for example "something happens" idk a curse?, aliens? magic? which turns your character into a futanari that wants nothing more than to fuck everything available. Ahhh god that idea is asuch a turn on for me! urgh!
But with lore and story driven things, you only limit yourself by yourself. You gotta remember its YOUR story/lore do whatever the fuck YOU want.
Im a little drunk sorry.