Today is Britney Spears’s 30th birthday and we're celebrating the pop star's big milestone with a roundup of her sexiest moments on stage! She's brought plenty of hotness since hitting the scene in 1999, including endless amounts of ab-baring ensembles and multiple envelope-pushing dance moves. When she's not out wowing crowds around the world, Britney’s sharing sweet moments with her family. Take a look at her sexy performances when you click through — happy birthday, Brit!!