John C. Reilly Reveals Disgusting 'Step Brothers' Fun Fact While Dishing on Method Acting

John C. Reilly went full method to pull off fart scenes in "Step Brothers."

The actor explained to Stephen Colbert on "The Late Show" Thursday night that he "farted on command," and was inspired to do so by master thespian John Malkovich. Both were once in the Steppenwolf Theatre Company in Chicago.

"So there's this legend about Malkovich," Reilly began. "That he was doing 'Curse of the Starving Class' in Chicago at Steppenwolf and his character has to pee on stage every night."

"The legend was 'Malkovich peed on stage for real every night,'" he continued. "And all of us were like 'No way, no way! I would have such a shy wiener. That's impossible! That's like real method acting.'"

Flash forward decades later to the production of his hit 2008 comedy co-starring Will Ferrell as his new adult step brother.

"There was a couple scenes where I need to fart, and I farted on command," Reilly said. "On camera. Actual farts. I thought like, 'I've got to a Malkovich level now because, you know, I can control my bodily functions for my acting.'"

In response, Colbert joked, "I could imagine at a certain point there, you're playing with fire."

"Do you still got it?" Colbert asked, and fortunately for the late-night comedian's audience, Reilly said no.

Reilly appeared on the CBS late-night show to promote "Holmes & Watson," his latest collaboration with Ferrell, hitting theaters on Christmas Day.

Relive their previous hilarity with one of the flatulent "Step Brothers" scenes in which Reilly went full method.

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