MASTER KEY

A girl asked her boyfriend, honey,why is it that when a girl have intimacy with more than one guy, she's a slut;people hate her, but when a guy does the same, he is a legend? the guy answered... "if a door is opened with more than one key, it becomes a useless door no one will want to keep anything important in a room with such door, but if a key opens more than one door, then its a MASTER-KEY