I once had the idea where the plot was you and your wife in the house. You take in a fat ugly middle aged balding man called 'Fat Dave'. You know where this is heading right?
Well the neighbourhood has all manner of people out for your wife: Blonde Bodybuilder, Black Guy, Annoying Ginger Lesbian, a Futanari you don't know is futanari. Now...when you are at home you can guard her, but you have to go to work don't you?
Well here's the twist: Fat Dave is in fact completely loyal to you and the more you chill, go bowling or whatever with him the more he will defend your wife when you are gone. Most players won't even think about it because the trope of ugly bastard NTR is so strong, so in effect players will be choosing to be cucked without knowing. The more Fat Dave likes you the sooner he intervenes: If he only likes you a little he waits until just before the moment someone tries to penetrate your wife, bursts through the door and *BONK*! hits them with a frying pan. If he really likes you then they don't even get to the doorbell and you see him chasing people round the neighbourhood with a frying pan as you return from work.
But the real kicker, is the moral choice of if you want to be cucked you have to be mean to Fat Dave and if you feel like you can't do it then you will cuck yourself from being cucked: Cuckception!