Christina Aguilera and husband Jordan Bratman
12/22/2008 at 01:15 PM EST
got all dressed up for her birthday – and not in a gown.
The singer celebrated her 28th birthday on Dec. 18 with a Clockwork Orange
-themed bash at Beverly Hills' SLS Hotel along with husband Jordan Bratman and pals Nicole Richie
and Joel Madden.
Arriving by a private party van, the singer and her friends headed into SAAM, the private dining room inside the hotel's Bazaar Restaurant, where she was greeted by waiters who were also dressed in their macabre Clockwork Orange
best for the occasion. Aguilera was also met with her favorite cocktail – the cotton candy mojito.
The singer and her 25 friends danced all night as DJ AM spun tunes for the crowd. And Aguilera ended the night with two sweet treats: a Clockwork Orange
-themed birthday cake and a sleepover with Bratman in the hotel's presidential suite.