Closeted Whore

A girl that you wouldn't expect to be a whore but she is in fact, one of the biggest whores in town. An undercover slut if you will.

Robert: Yo, this girl is a keeper man, she's literally so sweet.
Bob: Don't go for it bro, she's a closeted whore. Half the boys in town have ran through that.
Robert: Huh, I never would've guessed.