Gerard Butler ‘Almost Killed’ Hilary Swank On ‘P.S. I Love You’

Gerard Butler "almost killed" his P.S. I Love You co-star Hilary Swank. While appearing on The Drew Barrymore Show Tuesday (January 24), Butler, 53, played the host's favorite game, "Behind the Scenes." To play the game, Barrymore, 47, explained to say the first thing that comes to mind -- or a "naughty detail." As she went down the list of movies Butler has starred in, including The Ugly Truth, 300, The Phantom of the Opera, The Bounty Hunter and P.S. I Love You.

Butler explained that he went into filming P.S. I Love You with the intention of putting Swank's needs first. "I remember saying to the director:  'I'm not going to think about myself in this movie, I'm only going to think about her,'" he said. "Make sure she's okay, she's cool, because that's kinda who this guy was, and I'm gonna tell you, it made the experience so much more fun."

The actor then revealed that he injured Swank, 48, while working on the scene where he danced "like an idiot" in boxer shorts and a pair of suspenders. Detailing that his character, Gerry Kennedy, was supposed to get hit in the face with his suspender clip while getting undressed, he said the piece took off and hit Swank's head instead. The crocodile clip got stuck in the television, and as he crawled towards Swank in front of him, she laughed hysterically at him. The camera crew even had protective plastic because it was "so dangerous."

"It gets stuck, it releases [and] flies over my head, hits her in the head — slashes her head," he explained. "I cut her open. You could even see the teeth of the [clip]. She had to get taken to the hospital."

Added Butler: "Imagine this studio, and in three seconds, everybody's gone. And I'm just sitting there in my Irish [shamrock] boxer shorts and my boots and a pair of socks, and I just started crying. I was like, 'I scarred Hilary Swank! I almost took her eye out! And I just made a fool of myself for two days. This is all I have to show for it, she's off to the hospital. There's nobody on set.' I was like, 'God.' Talk about imposter syndrome."

Watch the interview below: