London, July 2 ANI: American actress Jennifer Aniston got socialite Kimberly Stewart booted out when the she tried to sneak backstage at John Mayer's recent gig.However Stewart was a little slow in getting the message and she had to be kicked out twice.Aniston knowing her beau's history with the model was very wary of her, especially when she spotted Stewart backstage while John was warming up for Sunday's Hard Rock Calling gig in London's Hyde Park.Mayer, who did not want to hurt anybody's feelings, got his security to boot out Stewart, while 39-year-old Aniston eyeballed her rival to warn her off."Jennifer spotted Kimberly and asked John what she was doing there," Daily Mirror quoted a source as saying."John and Kim know each other from clubbing in LA, but Jennifer doesn't want anyone around who reminds her that he used to be a player."She has fallen head over heels for John, but she's scared it will all go wrong again."Another woman stole her man before when Angelina Jolie started dating Brad Pitt - she couldn't bear it to happen again," the source said.But even though she had been asked to leave, ten minutes later she was on the side of the stage waving at Mayer and making cheeky gestures at Aniston."She had been told twice by security that she would be removed but she stood there bold as brass," another source said."Jennifer was on the opposite side of the stage and John felt like piggy-in-the-middle."He saw the tension and told his bouncers to get rid of her at all costs."Kim was pulled off the stage and escorted through the Hard Rock VIP tent with a face like thunder, shouting: 'Why doesn't he want me here Is this because of her' She totally embarrassed herself, but Jen looked relieved," the source added. ANI