Paul Bettany flew his children to the 'Legion' film set so they would think he was "cool".

The actor - who raises Kai, 12, and Stellan, six, with wife Jennifer Connelly - invited the trio out to visit him while he was working on the action movie, because he wanted his sons to be impressed with his "tough" screen persona and behave themselves.

He said: "I made them fly out to watch me so they'd think I was enormously cool and tough. And they will now do whatever I tell them to, because they think I can do a butterfly twist!"

Although the film - in which he plays an angel trying to save the world - was like nothing Paul had ever worked on before, he loved trying something new.

He explained: "I loved it. I'd never made an action movie before. It was such a great experience and I loved doing it. It felt fun. It was exactly what it was and I loved doing it.

"I was learning how to spin around in the air - a lot of wire stuff and a lot of fighting. I wouldn't say I know kung fu... they wrap a wire around you, and this guy yanks it, and you fly up in the air and spin - and because of gravity you can't help but land on your feet. Then you go and look at playback on the monitor, and you look like Bruce Lee!"