Spears throws birthday party for her sons

LOS ANGELES, Sept. 15 (UPI) -- Pop star Britney Spears held a joint birthday party for her two toddler sons in Beverly Hills, Calif., during the weekend, a source told Usmagazine.com.

Since Sean Preston, 3, and Jayden James, 2, were born two days apart, Spears reportedly threw one, car-themed bash for the boys Saturday at a friend's house.

In attendance were Spears's 17-year-old actress sister Jamie Lynn and her baby daughter Maddie, Spears's brother Bryan, her mother Lynne and her father Jamie.

"Britney was looking on like a very proud mommy," an insider told Usmagazine.com. "She got a kick out of watching the boys in their cars and was laughing and smiling."

Sean and Jayden, Spears's children with ex-husband Kevin Federline, were given tiny sports utility vehicles for their special day, the entertainment news Web site said.