They were wrapping up her leg of the Paisley Party Tour and Brad had yet to pull a prank on Jewel so she wanted to get him, and she did! It was awesome and I have YouTube video to prove it.
First she changed the video that runs behind him when he sings "I'm Still A Guy" so that his head was on all kinds of women. (that's important to know because he mentions it in the clip)
So get ready for a good chuckle.
http://www.youtube.com/watch?v=YndtwzAwEGM