Charlie Sheen's Twins Celebrate Birthday – Without Their Dad
03/13/2011 AT 05:10 PM EDT
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