Mila Kunis and Ashton Kutcher
Ashton Kutcher sought Mila Kunis' father's permission to marry her.
The 'Anger Management' actor - who was previously wed to Demi Moore - wanted to do things in a "traditional" way so sought the blessing of his actress girlfriend's dad Mark over the Christmas period ahead of popping the question earlier this year.
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 together since April 2012 and friends don't think they will have a long engagement, predicting they will tie the knot later this year.
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."
Friends previously said Ashton, 36, and his 30-year-old girlfriend are so well suited and content together, it is like they are married already.
One insider said last September: "They are clearly very much in love, in tune with each other and so comfortable.
"In some ways, it's like they're married already."
Tagged in Ashton Kutcher Demi Moore Mila Kunis