The singer shows off her toned tummy at a party thrown by another famous blonde in Los Angeles. Plus: More AMAs action, Matt McConaughey and more

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FLAT AS A BOARD

Taking a cue from her perpetually underdressed party host Paris Hilton, Britney Spears changes into a revealing outfit for a post-AMAs soiree in Los Angeles on Tuesday. Despite making the social rounds, the singer was said to be dismayed at a sketch during the awards that ridiculed estranged husband Kevin Federline.