Pop princess Britney Spears attended the birthday party of her husband Kevin Federline's two children.

According to the Internet Movie Database, Federline's former wife Shar Jackson was upset when Spears and Federline did not show up for her eldest son Kaleb's birthday party.

But Spears and Federline soon made up for that mistake by attending the other children's party held in Malibu, California.

A source says, "It was a cowboys-and-Indians theme, but Britney and Kevin were the only ones not dressed up. Britney and Shar hugged when Britney arrived, but after that they had no interaction."