As guests like McCarthy’s beau and Charlie Sheen and wife Brooke Mueller made the rounds, Spears, 26, sipped on red wine.
Carrey’s daughter Jane also belted out a few Frank Sinatra and Jackson 5 tunes.
Spears, 26, “definitely looked happy,” a witness tells Usmagazine.com. “She was clapping and smiling a lot.”
It was Spears’ first public outing since reaching a custody agreement with ex Kevin Federline last week.
While Federline gets sole custody, Spears gets three visits a week from Sean Preston, 2 1/2, and Jayden James, 1 1/2, including two overnights.
If all goes well, she could have her boys roughly 40 percent of the time, her attorney, Laura Wasser, has said.
Wasser told the Associated Press the “difference” in Spears “from the beginning of this year to now is astonishing.”
Spears is spending her summer recording a new album.
(source)
Lara's Wardrobe Cam
Test Your Knowledge
Who's the sexiest female singer?
Photos: Green Friendly Celebrities
Who's Hotter? Play Now

Britney Spear's new album is set to drop in December, are you planning on buying it?
