You're obviously a virgin if you don't know that during sex, pain gets turned into pleasure. You can rub your legs on the carpet, until you're raw, and not feel it until afterwards.
The sex drive in men, and all male animals, was developed to propagate the species. Since life is a competition, during sex dopamine increases, much like a drug addict. Otherwise you'd not be able to fight off another male trying to get your woman too. Which is also why taking steroids increases rage in men too.
But, we as humans, well most of us, besides Muslim barbers, wife beaters, etc, have learned to be civilized and developed compassion, so we don't force a woman.
Which doesn't happen in the animal kingdom. Are you so prudish you've never seen a male dog force itself on a female dog? You can't even separate them because they get locked until finished.
"The psychologists claim that in all cultures and throughout history, men have sought to get their way by initiating violence.
They prefer group-based hierarchies and are identified more strongly with their own groups than women.
At a basic level, such ‘tribal’ aggression helped men in a group to obtain more females, increasing their chances of reproduction."
http://www.dailymail.co.uk/sciencetech/article-2090226/When-men-war-blame-sex-drive-Males-evolved-aggressive-outsiders.html
