I'd like to see a game in which the MC wins over someone that she shouldn't be with according to societal norms. I mean in the way that she, being the mistress of her own life, really wants someone that she knows she shouldn't want but can't help wanting BAD, who in turn has major issues with the whole concept of them being together. Obviously, after much toil - as the game progresses - she gets to reap the fruit of her labour in the end.
It could be a forbidden love story, which I would prefer, but also just forbidden fruit in general. So long as she is in control and wins that other person over, rather than simply manipulate them into having sex with her. I don't really care - it being a lewd game where fantasy gets to play out - if it's her sibling, her parent, the principal of her highschool, or whomever. So long as she is the one initiating the relationship and the other is the one who is reluctant to being pursued. I think it would be very intruiging to play such a game.
For example, imagine that a heroine like Ellie from TLOU2 has secretly harboured romantic and sexual feelings for Joel these past few years. He, on the other hand, views her like a daughter (yes I know there's a lot more to unpack in that relationship, but just bear with me). Imagine a game in which you play Ellie and your goal is to get Joel to stop viewing you like a little girl he needs to protect and, instead, start seeing you like the strong, independent woman you've become - and to make him fall for you.
It really doesn't have to be about a young woman longing for an older man at all, though - certainly not. I just wanted to paint a more vivid picture of what it could look like with this concept of a hard-won and (in the eyes of society) questionable relationship, growing out of near impossible beginnings.