Charlie Sheen’s twin sons, Max and Bob, celebrated their second birthday over the weekend with a lavish party — but without their dad, according to Us Weekly. Sheen is currently locked in a nasty custody battle with the twins’ mom, Brooke Mueller, who has a restraining order out against the troubled former Two and Half Men star. "Brooke seemed to have a good time, too, and was relaxed and happy," said the source. "She seemed focused on her kids and nothing else. There was a lot of security outside at all times to make sure no uninvited guests got in. There was no sign of Charlie at the party."