Very into this. Maybe it's when I first "walk in on them." He's already stripped down to a pair of boxers and isn't happy to be interrupted when he's about to gett his dick wet. I try to stand up for myself and tell him to get lost.
He's way bigger than me, grabs me by my shirt collar and lifts it up. In the process my shirt and under shirt are ripped off, leaving me bare chested. The contrast is stark between his big hairy chest, his manly beer gut, and my mostly hairless chest, tight abs. I foolishly lunge at him and we wrestle. Pretty soon he's stripped me of my pants too, so we're both fighting bare ass. He eventually pins me, his big hairy ass sitting on my chest, his dick inches from my face. The comparison between his big man cock and my tiny little boy pecker makes me die of shame. Keeping me pinned, he slaps me in the face again and again and the tears start rolling, to his jeering delight. At this point I am his, begging for mercy. He spits in my face, then makes me open my mouth. He hocks a big thick loogie right down my throat, makes me swallow. The final humiliation is that he makes me kiss his cockhead reverently, which has gotten hard. My wife watches me suck cock and will never be able to see me as a man again.
I'd want it to be more about humiliating me and destroying my status as a man as opposed to injuring me, but I'd want a couple good punches to the face. That way I have to walk around with the black eye and fat lip he gave me, knowing I had been conquered by the man who fucked my wife.