Viggo Mortensen has a pronounced scar on his upper lip that not even makeup can conceal.

The sexy star of such films as A Perfect Murder, Crimson Tide, GI Jane and this Friday's romantic drama A Walk on the Moon says the scar is a reminder of his reckless youth.

"It was a combination of a fist and a barbed wire fence on a particularly bad Halloween night. I was 17 and so drunk that I didn't even need an anaesthetic when the doctor sewed me up," recalls Mortensen. "When I got out of surgery, my friends had ordered pizzas to the hospital and I helped them eat them."

When Gwyneth Paltrow and Ben Affleck split up last fall, supermarket publications claimed it was because Paltrow and Mortensen had made their steamy sex scenes in A Perfect Murder a little too perfect.

"I had a great sex scene with Christopher Walken in The Prophecy and no one started rumours about us. When will people realize that actors act? If we didn't make love scenes believable, we wouldn't be doing our job properly."

Mortensen has three steamy sex scenes with Diane Lane in A Walk on the Moon, so he says he'll start checking out the supermarket publications the following week.