LATEST: Pop star Britney Spears has quieted tabloid rumours is pregnant with her second child by sipping cocktails in a Las Vegas, Nevada restaurant. The TOXIC singer was celebrating husband KEVIN FEDERLINE's 28th birthday in Sin City on Tuesday night (21MAR06) with a decadent dinner at Tao restaurant. Although Spears was seen knocking back the cosmopolitan cocktails (vodka, triple sec, cranberry and lime juice), she still seemed to have an appetite for two, devouring spare ribs, crispy tuna, pork rolls, lobster tempura and Chilean sea bass, among other Asian delicacies at the hip nightspot. After the main course, Federline's birthday cake was delivered by two female "little people", who climbed atop a table to sing, "Happy Birthday", according to the New York Daily News. The couple then moved the party to Pure nightclub, where Spears was seen kicking off her shoes and dancing to music by Prince.