I'll gladly get my ass kicked, but nobody is R'ing my girl. That's a quick way to get a bullet to the skull or a knife to your spine. The fantasy may be hot, and I know alot of women (having dated some) have a R fantasy, but no victims in fantasy.
I don't care about getting slapped or punched in a sexual situation, but fucking my girl is gonna be 100% consensual. You've got a bigger chance of convincing her to hit me, slap me, or even thanking you for making me look like a pussy instead of keeping me from stopping her being R'd.