Optional... ohhh thanks for that! not all devs think about all their fans, in my case I mostly despise NTR and I like incest, a bit contradictory considering that if I fuck my mom I'm cucking my dad/step-dad lol anyway, in the case of your game I have the NTR ON, not only because it's more challenging but also because the husband is an asshole! and when the husband is like that I want to see the wife fucking everything, her son, an stranger, anything!
Anyway, again... thanks for making everything optional, if someone ever complains, just remind them that you gave them the option to choose.