Any activity in sex involving a couple, no matter how hardcore or vanilla it is, needs to be consensual or it isn't said activity. If you see any amateur porn video where the woman didn't consent, you're not watching a woman having sex, you're watching a woman being raped.
Even fictional characters can say no, you know? As long as the dev wrote that, if she says no, it means no. Then, if the game allows you to the thing she doens't want to do because it's a porn game and the final idea is pleasing the player, and if the woman ends liking it because of your magic dick and porn logic, that's another topic, but if you can't believe in the NPC's word when she says no just because she's fictitious, why will you believe the MC when he says he likes women and not men? He's just another fictitious character after all.