Ashton Kutcher refuses to "punk" his movie co-stars.

Ashton Kutcher refuses to "punk" his movie co-stars.

The 30-year-old star - who plays practical jokes on fellow celebrities for his MTV show 'Punk'd' - won't target his colleagues because he is afraid of being blacklisted in Hollywood.
He said: "If you punk your co-stars, people don't want to work with you any more. So I don't do it, it's that simple."
Cameron Diaz, who stars alongside Ashton in new comedy 'What Happens in Vegas', believes