Ashton Kutcher asked Mila Kunis' father for his blessing to marry her.

The Hollywood hunk wanted to take a ''traditional'' approach and decided to have a chat with his girlfriend's dad, Mark, over the Christmas period before he popped the big question.

A source said: ''He talked with Mila's dad around Christmastime.

''He asked for Mark's blessing to marry her. It was important to Ashton to be respectful and traditional. This is the real thing for him and he wants to do it all right.''

The former 'That 70s Show' co-stars have been dating since April 2012 and friends reckon they'll tie the knot later this year as they ''don't want to wait.''

One friend told People magazine: ''They don't want to wait.

''This relationship started on solid ground and everything is working out. They are in it for the long haul, truly.''

Ashton was previously married to Demi Moore and their divorce was finalised in November 2013.

Meanwhile, Mila previously dated 'Home Alone' star Macaulay Culkin. The pair began dating in May 2002, but in January 2011 her publicist confirmed reports that they'd ended their relationship.