I can't believe this has happened.
He just remains stood up there on the middle of the stage waiting for the vomit to come out I would have done the impossible to try to run away and not to be noticed. What a shame!
I wonder if this has anything to do with him trying to go vegetarian/vegan like Usher wanted him to. I heard on Ryan Seacrest's morning show that he had tried some tofu at a restaurant and gagged it back up immediately.