The former ‘Two and a Half Men’ star and his estranged wife Brooke Mueller recently agreed a custody agreement over two-year-olds Bob and Max after a bitter battle but despite this and Charlie’s erratic behaviour, the boys seem to be thriving.

Paris Hilton’s mother, Kathy – who is good friends with Brooke – told E! Online: "They are the cutest, happiest babies. They were just sitting in the high chair and Bob had the remote. We TiVo ‘Two and a Half Men’ because it's our favourite show. Bob saw something with ‘Two and a Half Men’ and he goes 'Dada!' "

Bob and Max are already showing signs of different personalities with one inheriting some of Charlie’s traits.

Kathy’s husband Rick added:

"Max is just like Charlie, where he's real serious and he looks just like him. Bob is more lighthearted and fun."

The boys celebrated their second birthday at Kathy and Rick’s Los Angeles home last month and while Charlie wasn’t there, they insist he would’ve been welcome.

Kathy said: "I hosted the party and it's not my place to decide who to invite. I adore Charlie! He's a neighbour of Paris' but that's kind of between them [Charlie and Brooke]. Maybe he was doing his own party so I didn't do the guest list."

Charlie and Brooke – who are in the process of finalising their divorce - reached a custody agreement last week and while Brooke will remain primary carer of the boys, Charlie will get to take them every other weekend from Saturday morning until Sunday evening for the first two months.

For the two months after that, the alternative weekend visits will be extended so Bob and Max stay in Charlie's care until Monday morning.

From then on, providing the 45-year-old star stays clean of drug and alcohol, he will be allowed to take the twins every other weekend from Saturday until Monday and also on Wednesday mornings until Thursday.