The Lethal Weapon star who confirmed he and Oksana Grigorieva are expecting their first child together earlier this week and the Russian pop star do not share a home as Oksana doesn’t want to disturb the life of her 11-year-old son, whose father is actor Timothy Dalton.
A US magazine said: “At the end of the evening, the couple typically return to their separate homes so Oksana can get her son Alexander off to a local school in the mornings.
Oksana, 39, is determined for Alexander and Mel – who has seven children with estranged wife Robyn – to be friends in time for the arrival of the new baby.
The source added to People magazine: "It seems very important to Oksana that Mel and her son bond. Mel is fun to be around and great with kids.
"Oksana is a good mother and she'll make a great mother to Mel's child. She's found the greatest thing in life, someone to take care of her and a father to her children."
Robyn filed for divorce in April, citing "irreconcilable differences", and she is expected to get half his £450 million fortune.