Matt Damon is great friends with his girlfriend Luciana Barroso's five-year-old daughter, but insists he is not taking over the "daddy role".
The 33-year-old star brought aspiring interior designer Barroso, her mother and Barroso's daughter to Sydney last weekend for the Australian premiere of The Bourne Supremacy.
Damon explains: "Without talking too much about her, because she's five and she didn't sign up for this, what I could say is that I am definitely not playing daddy.
"She's got a great father, you know? The two of them split, but they're great parents in their own right."
But the Oscar winner admits he can relate to the child, because his own parents divorced when he was young.
Damon says: "When my parents split, and they are both great parents. My mother had a man in her life for 16 years and that guy was a very positive influence in my life without ever trying to be my father. So I have some experience of that kind of dynamic and so far it seems to be going well.''
And when asked at the premiere if he plans to wed pretty Barroso, Damon replied: "Whenever I've been in a relationship, whether it's with a friend or a girlfriend, generally they're going to have qualities that, you know, make life more fun, happier, easier."