Keith Richards ''intimidates'' his daughters' boyfriends with knives.
The Rolling Stones rocker is very protective of 26-year-old Theodora and 25-year-old Alexandra - his girls with wife Patti Hansen - but trusts their instincts in knowing what makes them happy.
Alexandra said: ''He's quite protective. Sometimes it's hard for him. Sometimes he takes boyfriends to the other end of the house to show them some tricks he can do with a knife to intimidate them a little, to warn them that they shouldn't make me or my sister suffer. But then he's very pleasant.
''I think he trusts my instincts and that I know what makes me happy.''
Alexandra - who is dating DJ Nick Cohen - also works as a DJ and says her famous father is very proud of her career.
She told Hola! Argentina magazine: ''He came once with a friend to the bar where I started out. Luckily, it was a quiet night. There was hardly anyone there and no one bothered him. I took the opportunity to put on all his favourite tunes.
''He's very proud of my work. When my picture comes out in the papers, it can make him cry.''