Lady Gaga branded 'a childish diva'

Lady Gaga was branded 'a childish diva' by Vogue editor-in-chief Anna Wintour, according to the singer's biographer.The British-born journalist met GaGa back in May when she performed at Anna's Metropolitan Museum Costume Institute Gala. "She (Lady GaGa) sort of had a meltdown before she went on and as it was described to me, Anna was really none too pleased with her. Anna wasn't impressed. She thought she was just behaving like a childish diva and not the professional who was about to perform for her peers; these incredibly famous designers and celebrities," the Sun quoted Maureen Callahan, author of much-anticipated biography 'Poker Face: The Rise and Rise of Lady Gaga', as saying."She sequestered herself in the back room for a good hour. She was late to perform and I also heard that she had been demanding things. She went to Anna at the last minute and was saying, 'I'd like it to be this way."And Anna just said no. I don't think she's used to hearing that very often. When you're dealing with two egos like that, it gets interesting," she added.