Typically the boyfriends of such girls will convince them that, if they take it in the ass and don't pop the cherry, they're still pure and virginal.
Guy 2: "Just explain the poophole loophole to her and you'll score for sure."
Chick: "Thank goodness for the poophole loophole. Now I can honestly tell God and my parents that I am a virgin."
She: It's okay...we can use the poop hole loop hole and you can do me in the butt!