Sure it’s fun to take swipes at your ex, but experience tells me that if you feel the need to take a dig, then you’re still in the ditch. Selena Gomez appeared on Letterman, who set her up for a well-timed joke when Letterman informed Selena that he made Justin Bieber cry. Selena’s response? “That makes two of us.” She also gave a Cheshire Cat smile, and said, “I’m so good,” which also leads me to believe the opposite. She’s clearly not over it, and her public put-down only served to take herself down a peg. WATCH BELOW.