Humans are pretty durable. If you’re having sex with a woman such that it makes her cry, you’re possibly doing damage to her reproductive system. Even 5k years ago, humans had a high investment reproductive strategy, and if you (as a historical man) injure a bunch of women during sex and leave, those women aren’t going to be in a great position to raise your child for fifteen years.

Also, while rape was absolutely more common historically, women have often had some say in things. If you look at Lysistrata, for example: the women decide to withhold sex until their husbands stop fighting. One suggests that their husbands will just have sex with them anyway, and the group reassures her that if she doesn’t enjoy it, he’ll lose interest. That’s pretty common for people- they want sex to be positive for both people involved.

Also the practical aspect of- a person you have sex with probably has access to you in a vulnerable position and you don’t want them to hate you.