Ohhh, it's on now! Shortly after rumors surfaced that Disney startlet Selena Gomez is dating Miley's ex, Nick Jonas, a new YouTube video of Miley and her BFF Mandy has hit the net featuring the two blatantly mocking a video created by up-and-coming tween sensations Selena and Demi Lovato (also best buds). Now, now, Miley. Is that how we treat our fellow Disney princesses? Jealousy is not becoming on you.