For awhile I've really wanted to play out a secret baby scenario. Like, a couple, who has a passionate but chaotic dynamic, breaks up, and the female character ends up just pregnant. She goes through with having the baby and raising it on her own until they meet up a year or so later. I've played out a scenario similar to this, but it wasn't quite the same, and we didn't get much of a chance to explore the situation or let it play out.
I also really enjoy betrayal in stories, and since I started playing an older rpg that has a great "MC is actually a secret bad guy" twist, I would love to incorporate into my own story. Something of a "Lovers to enemies (but also still lovers)" dynamic. No non-con, unless the idea was to break up the couple (becuase I don't really like non-con in ship I am supposed to root for), but maybe some light dub-con. Really, I want to explore a couple who care deeply about one another, and are very sexually attracted to one another, but have opposing goals and/or value systems. I don't know, it might be really hard to pull off, but it's a pretty intense craving right about now.