I think a lot of men view hetero Sex as being about dominance, not pleasure. They fuck women because it’s What Men Do or because they want other men to admire them or because that’s what they think being happy is for adult men. It’s not about pleasure or joy.
I think they fuck men for the same reason they grope Brazilian women or fantasize about fat women. They want to feel something more but they’re afraid. They probably don’t even really know what they want.
So they break the rules when they can.