No NTR route? Really poor vanilla history then.
I want to address this, not because the comment deserves it, but, because I feel like it.
NTR, would require other males that would compete with the MC for sexual favors with the girls/women, apparently, this story happens in a town/city/village/whatever where men are a rarity, not only that, but they are all subpar humans, or, have strange fetishes that don't align with the girls that are interested in our MC. So, not only there's a severe lack of men, but also, those that exist are trash or unavailable...
Hmm, kinda difficult to establish a NTR route. Also, our MC is a decent guy that treats the girls/women quite decently and satisfies them sexually, again, it makes things harder to achieve.
Next, our MC makes it clear that he wants the girls/women to be his ONLY and makes it a condition, they either accept it, or, no deal, so, the type of woman that would cuck him, wouldn't be in his relations... therefore, no NTR.
So, sorry to say, but this particular kink is completely out of place in this game. Complaining about that is as fruitful as screaming to the rain to stop.
My advice? Move on. Just a small hint, if you ever only want NTR content, maybe not look for it on a Harem game? They kinda negate each other, no?
Good luck on your quest for humiliation, may the other guys be ever bigger than you... or whatever your kink is...
Peace