She probably could have puked backstage, before the song, but after seeing how viral Justin Bieber's vomit episode went, who wouldn't want to throw their hat in that ring? The best part is the dude dancing with her saw her barf and just kept on going. Danced his fuckin' heart out while she held her own hair and puked two more times. But he didn't miss a beat and I can't blame him. Probably realized someone would get this on YouTube, couldn't squander the opportunity.