Double Standards
They don’t make sense when it comes to gender double standards (and usually never, if at all). This is a great example of one of those standards. It’s natural and enjoyable for two people who consent to have sex! There should be no shaming towards the other person in a healthy relationship, regardless of how many sexual partners they’ve had previously!
However, everyone should, together, shame individuals who have abused others sexually. Men must realize that there is never a justification for sexually abusive behavior, and calling someone out is the proper thing to do!