On live television, anything can happen. And when you’re a live comedy show going strong for the past 50 years, like Saturday Night Live, you’re bound to experience some outrageous, profane, and just plain rude behavior from celebrity hosts pushing the boundaries. In all the years SNL has invaded our weekends, a little over a dozen performers and guests have been barred from ever returning to the legendary studio, whether due to their attitude, their backstage antics, or an on-air stunt that left the show embarrassed. We’re looking at you, Adrian!