The pop star, who actually turned 26 on Sunday, partied with old pal Paris Hilton at a mansion in Bel Air, Los Angeles.
Spears chose the venue because of its Scandinavian looks. The singer's cousin and former assistant, Ali Sims, and dancer companion Sam Lutfi also partied with the pop star, who last week denied reports she's pregnant with music producer J.R. Rotem's baby.
Wearing sexy black lingerie and a black bow tie under a white fur-lined jacket, a smiling Spears celebrated her birthday at midnight with a chocolate cake.
COPYRIGHT 2007 WORLD ENTERTAINMENT NEWS NETWORK LTD. All Global Rights Reserved.