I understand your thinking that(even though I have to disagree). That's because I don't see such humiliation in that part of the game (again I can understand why you do).
(I think there's even a chance that scene isn't shown because the author didn't want to animate it. But I'm not going to say that's a fact)
The only thing I can say is that that's the only instance where something like that happens in the game so you don't have to worry about it (I've played until the end of the available missions).
The most problematic thing about the game (in my case) would be the excessive exhibitionism, and some cases where you have to save your girls (nothing happens but the possible NTR plot is there).
Again I'm not trying to change your opinion. But I reiterate everything Zoe does is so you can fuck Abby at the end. Zoe and Abby don't have more intimacy behind your back after that as far as i remeber (even there is a change to get to see them fuck, if you want it, in some of their next missions). And Zoe wanting to cuck you is out of character (she got pretty upset when she found out what the MC's ex-girlfriend did)