Kevin Federline Parties while Britney Spears in Rehab

Super Dad Kevin Federline spent Saturday night in a Las Vegas nightclub while his estranged wife Britney Spears relaxed at the Promises rehab facility in Malibu, Calif reports Star Magazine.

"Kevin came in at about midnight with about 15 friends to the new club Revolution, and left at 3 a.m.," a source tells Star. The DJ was playing Justin Timberlake's song "Sexy/Back" when Kevin arrived, but then the music switched to oldies. When Bon Jovi’s "You Give Love a Bad Name" came on, Kevin's friends sang to the chorus and pointed at Kevin as he sat there and smiled. "Kevin then looked at the crowd and said, 'Federline's in the house!' and high-fived the DJ," an eyewitness tells Star.

Kevin kept it low key, even playing Tic-Tac-Toe on the interactive light table. "He really just hung out with his immediate group of friends all night, though there were plenty of girls trying to get into the VIP area to meet him," the eyewitness tells Star. "The only girls around him were girls he brought, but they all said they worked for him somehow."