The on-set incident was all thanks to a pair of suspenders and a raunchy dance scene.

Gerard Butler still feels terrible about what he did to his co-star, Hilary Swank, on the set of their 2007 romance, P.S. I Love You. During a recent episode of The Drew Barrymore Show, the 53-year-old actor revealed that he “almost killed” Swank while they were filming the movie.

It all happened thanks to one lighthearted scene where Butler’s character, Gerry, is dancing shirtless in a pair of suspenders.

“I literally shot that scene for a day and a half and I had to dance like an idiot in the suspenders,” Butler explained. “At one point, the clip, which was a crocodile clip, got stuck in the television as I’m crawling towards her and she’s right in front of me and she’s laughing hysterically.”

He noted that the clip on his suspenders was “so dangerous” that the camera crew used plastic covers to protect themselves from it.

Warner Bros.
“I had to ping it, and it would go past my face. And this time I’m crawling towards the bed. It gets stuck,” he said of the clip. “It releases, flies over my head, hits her in the head, slashes her head. I cut her open.”

He added that Swank was rushed to the hospital, leaving him in tears on the set.

“Imagine a studio and in three seconds everybody’s gone, and I’m just sitting there in my boxer shorts and my boots and a pair of socks and I just started crying,” he said. “‘I just scarred Hilary Swank!’ I almost took her eye out and I just made a fool of myself for two days and this is what I have to show for it. She’s off to the hospital.”

Luckily, Swank made it out of the experience unscathed. The 48-year-old actress is currently pregnant with twins and recently opened up to ET about the experience. Watch the clip below for more.