Selena Gomez has been taking passive aggressive digs at Justin Bieber since they first broke up, and she kept the momentum going with her Monday night interview on 'The Late Show With David Letterman,' where she and the adorably gap-toothed host poked fun at her ex's misery.

And this time instead of doing a lame dance, Gomez was actually charming and funny.

Letterman asked Gomez if she was dating anyone, and she confirmed with a sly giggle that she was single. Innocuous enough, right?

However, Letterman, who has never seemed to be a big fan of the 'Baby' singer, brought up a previous encounter he had with Bieber.

"Now, the last time he was on, he and I got into a conversation," Letterman said. "He said something, then I said something, then he said something ... and I made him cry."

Gomez laughed hysterically, then deadpanned, "That makes two of us."

The 'Spring Breakers' starlet was visibly pleased with herself, but we're going to cut her some slack -- because we were pretty pleased with her too.