"I wanna say thank you to Christina Aguilera because that was a surprise. It wasn't planned at all. She said, 'I might go out there, I might not', because she had the set right before us... Next thing I know... she's next to me, I was like, 'Hey! Woah, oh, this is great!' And she's definitely got some things to look at. That's what made it even more stunning!" Rapper Pitbull was pleasantly surprised when Christina Aguilera joined him onstage at the American Music Awards on Sunday (18Nov12).