Aaron Johnson has become a father.

Sam Taylor-Wood - the 20-year-old actor's fiancee - gave birth to a girl, who they have named Wylda Rae, yesterday (07.07.10).

Aaron's 'Kick Ass' co-star Christopher Mintz-Plasse confirmed the news, writing on his twitter account: "Crazier news. Aaron Johnson's baby was born! So exciting!"

This is the first child for the couple who met on the set of John Lennon biopic 'Nowhere Boy' last year.

The pair live together in an £11 million north London townhouse, along with 43-year-old Sam's daughters from a previous marriage, 13-year-old Angelica and five-year-old Jessie.

Aaron has previously insisted he doesn't care about the 23-year age gap between him and the artist-and-director.

He said: "To be honest, I've never really lived life by the rule book. I've had a different life to most people. I've had to be independent and take on a lot."

Sam also defended the relationship in May, saying: "I'm in love, I'm blissfully content. No one's getting hurt. We're in a loving relationship. We're engaged. Everyone who matters is happy. Exactly which bit of that do I have to defend or apologise for?"