Have you ever had a severe case of the church giggles? That’s what happened to The Tonight Show host Jimmy Fallon and his guest Bradley Cooper. The Oscar-nominated actor, 39, was visiting the late-night show to promote his upcoming stint on Broadway, starring in a revival of The Elephant Man.

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Though the play and subject matter — about the real life of Joseph Merrick, whose deformities landed him in the traveling freak show circuit — are very serious, Cooper and Fallon, 40, struggled to make it through the interview without laughing when they started off the evening wearing over-the-top visors with spiked wigs.

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“Anyway, I went to London, went to see his bones, and it was amazing,” the American Hustle star said before busting out laughing.

“We can’t use this, we’re going to have to reset,” Fallon, who was notorious for breaking character on Saturday Night Live, said, giggling. “We’re talking about the Elephant Man’s bones and wearing these hats. You can’t have a serious conversation with these hats on.”

Throughout the 10-minute clip, the host continuously was forced to reset, trying to allow his editing staff a chance to cut out the parts with laughter. But the task proved impossible when the pals couldn’t stop roaring.  

“You know, it’s not funny, this guy was horribly deformed!” the upcoming stage star said, his whole body shaking. “It’s not funny at all.”

At one point, Cooper walked off the stage and Fallon fell out of his chair laughing.

The Elephant Man starts previews on Nov. 7 and ends its run on Feb. 15. Watch the entire, uncut version now!