If I remember right, the Creator said that he doesn't want to add rape sex, so I think this is hard to get in the game, but I was think something like a enemy that when your character defeat them, you can ask for sex. Then you can choose the position, and you unlock more position when you defeat they more times. And some special position for a character that is set to be your partner, with someone like this, you can make threesome(but still make without him) and some sex scenes in the town.
Nice! Actually, it would be a surprise for me if rape will be added since currently it have no gameplay meaning. You can't get pregnant or receive a statistic or your "sexual life" so rape wouldn't do a thing but humiliate you.
I see only one way it can be used in gameplay: a very strong enemy (boss) took most of your HP and you have a choice: die or watch a long scene (kill your time) to put boss into stun where you can either heal yourself or put final strikes. (In my opinion this is bullshit because you need to balance it a lot + it's a little cheaty)
Rape is so common in nsfw games, I prefer a "fight pass" to fuck with a npc, like a line that each time you defeat the npc you unlock a different sex scene, you been top or bottom. Other thing is toys, would be nice if you could buy or even create one with materials that you get is some places (like the tombs or from the skeleton) that you have some "solo scenes" in your house.