Brooke Mueller with her twins, Max and Bob
03/13/2011 at 04:00 PM EDT
Charlie Sheen's "winning" ways didn't score him an invite to his sons' birthday party.
The troubled actor
's boys, Max and Bob
who turn 2 on Monday, celebrated at a party Sunday with their mom, Brooke Mueller, and about 50 guests.
"The party is a casual and child friendly celebration," a source tells PEOPLE of the bash at Kathy and Rick Hilton's Bel Air home. "It's all about Max and Bob and their friends. They seem to be having a great time, and so is Brooke."
Sheen was never expected to attend.
Well-known guests included The Real Housewives of Beverly Hills
star Adrienne Maloof, along with her husband and kids.
The backyard of the Hilton home was decked out with balloons and decorations for the event, and the kids (who make up the majority of the guestlist), ran around together while the adults socialized.
And it looks like Max and Bob scored grabbed a haul: Guests arrived with lavish presents, including huge gift baskets, books and games, and matching push cars and clothes.
Reporting by PERNILLA CEDENHEIM