Whoops! During her Circus tour, Britney Spears made a big oops! After performing "I'm A Slave 4 U," Brit was lowered underneath the stage for a costume change. Well, her mic was still very much on, and the entire audience heard Brit say, "My p---- was hanging out!" Of course, since Britney doesn't exactly sing live, we're not exactly sure why her microphone was on. But, more importantly, how inappropriate and embarrassing!