Britney Spears knows a lot about pushing the boundaries at the VMAs, but tonight she even looked amusingly overwhelmed by Lady Gaga's gender-bending alter ego, Jo Calderone. Before Britney received the Michael Jackson Video Vanguard award, Lady Gaga — I mean Jo — confessed that Britney posters hanging on his bedroom wall used to turn him on and eventually got the audience to rise for a standing ovation for Britney. But that's not all Jo Calderone wanted to give Britney. On stage, Gaga and Britney awkwardly teased us with the prospect of a girl-on-girl kiss, à la Britney and Madonna, but Brit ultimately decided against it, saying: "I've done that already." Not quite, Britney — this would be a girl-as-boy-on-girl kiss.