Now that Jackass Presents: Bad Grandpa is a bona fide hit, earning over $66 million at the domestic box office so far (and climbing), we felt it was the right time to unleash Johnny Knoxville’s fond memories of pulling off the movie’s most hilarious prank: the male strip club sequence.

For the uninitiated, Bad Grandpa is a combination hidden camera prank flick and narrative road comedy that centers on Irving Zisman (Johnny Knoxville, also co-writer), an 86-year-old curmudgeon whose wife has just passed away. When his daughter reveals she’s going to prison—at his wife’s funeral, no less—Irving is tasked with transporting his 8-year-old nephew, Billy (Jackson Nicoll), across the country to his biological father. Hilarity ensues.

There are a number of gut-busting moments in Jeff Tremaine’s film, from Billy pushing a drunken Irving through a drive-thru in a shopping cart to Billy dressing up like a girl and participating in a beauty pageant. But the funniest moment of the movie is undoubtedly the male strip club sequence [below], where a boozed-up Irving dodges a gaggle of sculpted male strippers while revealing his impossibly long, wrinkly ball sack.

Here’s Johnny Knoxville on the Bad Grandpa scene that made everyone lose their shit:

“Oh, man. This was so much fun to shoot. I talked to the guy in the green camo that I targeted, whose name was ‘Climax,’ and afterwards, he said, ‘You know what? I’m a welterweight boxer’—and he had a great record. He said, ‘I almost put my hands on ya.’ We knew that it could go pretty bad—that Irving could get stomped tonight—and that was the best-case scenario. Before the dancers came on, I spent 45 minutes in the strip club just walking around talking to people, and while I was doing that, I was drinking so much because I was excited about what was going to happen. So, by the time things went down, ol’ Irving was half in the bag. By the time I started chasing everyone around the dance floor with my balls hanging out, I wasn’t Irving Zisman anymore, but drunk Johnny Knoxville just jumping over railings and harassing everybody. It worked! But I got a little too excited.

We always have an ‘in’ when we do a public prank, and one of the dancers there was our ‘in,’ who put on shows there. It was in a rough part of town, and we knew we were going to be in there for about four hours and have all these hidden cameramen, and cameras hidden in the ceiling, and speaker cases that our cameramen are inside shooting from. It’s hot in those speaker cases so the cameramen have little plastic bottles they pee in because they’re trapped in there so long. It was a difficult one to pull off! The ball sack is made of silicone, and we first did a balls bit in Jackass Number Two, and after that I kept the balls! I wore them every day, and at first, I’d just wear them to play pranks on someone and drop my pants and you’d see these old balls hanging down, but it got to a point where I was wearing them when I wasn’t pranking people. Finally, I’m at the house one day with Dmitry and we’re watching football, and he goes, ‘You’re wearing the balls right now, aren’t you?’ And I said, ‘Yeah…’ So, then I realized I had a problem and had to stop wearing the balls so much. But long story short, we had to get a new pair of balls for Bad Grandpa because I wore the other ones so much.”