“It didn’t mean anything. Why can’t you just let it slide?”
It’s true that men and women see sex very differently, but most people are aware of this rule and conduct themselves accordingly. Men understand that intimacy is a deep issue to women, this is why most guys choose to be monogamous when a commitment is established.
If you really believed that it didn’t mean anything and you didn’t do anything wrong, then there would have been no reason to cover anything up. This would be why a scorned love can’t “let it slide”