For what i have played in the demo, if you like ntr you can have, if not, you can combat the game like a normal rpg maker game (slash/fire,etc) and defeat the enemy, without him fucking your girl. But from what the dev said to me:
"the MC won't be the only one fucking the girls, that's for sure, but if you want to have only Lothar fuck the girls, no problem full scene will be optional"
So i guess there is stuff that or you see or don't, but you cannot change the girls fucking others, at least in the history (not combat). I hope that he make everything optional, if you want them fucking others you can, or be only you, but look like there is stuff that don't matter what you do, they will fuck, you can see or not.