Hollywood hardman Sean Penn tried to bully his daughter's first boyfriend into keeping his hands to himself but the lad just laughed in the actor's face - because he was a deadly martial arts expert.

The Milk actor dreaded the moment Dylan Frances, his daughter with second wife Robin Wright, started dating and admits he was well prepared to play the protective father by the time she reached 16.

However, his well-meaning veiled threats to the first boy Dylan brought home had no effect whatsoever as he was a champion fighter.

Penn tells U.K. talk show host Graham Norton, "She was 16 when the first one came to the door, so that was 16 years of waiting for that moment. I ordered her to her room because it was my night! I was very nice but said, 'You need to get my daughter home early and if you don't, whatever you do with her while you are out, I will do to you when you get her home!'

"I thought his laughter was nervous laughter but it was laughing at me. It turned out he was a three-times mixed martial arts champion and he found the whole threat pretty humorous."