“Hey, how old are you, anyways?”
“Me? Twenty-two.”
“Like fun you are.”
It was a funny thing to say. It sounded like a real kid. You’d think a prostitute and all would say “Like hell you are” or “Cut the crap” instead of “Like fun you are.”

J. D. Salinger

The Catcher in the Rye. Chapter 7. A prostitute who won’t use profanities! Holden recognizes a kind of innocence in Sunny. Which means he can’t have sex with her – “I felt more depressed than sexy, if you want to know the truth.”