Evan Peters on the time he accidentally showed Jessica Lange his junk

Evan Peters has shown a great range of acting skill on American Horror Story, but behind the scenes, he’s showing off some skin, too.

Peters revealed on Conan Tuesday night that he had accidentally flashed costar Jessica Lange his genitalia for an entire scene without even knowing it.

“Wow, this is terrible,” Peters told Conan O’Brien. “I basically am leaned over Jessica Lange’s desk in a hospital gown, bare-ass, so I put a c— sock on.”

For those unfamiliar, that’s a “term, a rather crass term, a technical term. It’s supposed to cover the entire genital region,” O’Brien explained.

“I put it on, and we did the scene, and afterward, Sarah [Paulson] comes up to me, kisses me on the cheek, and is like, ‘Oh, sweetheart, it’s OK.'” Peters recalled. “And I was like, ‘What, was I that bad?’ And I look over and Ms. Lange is telling the PA that apparently my balls were in her face the whole shot. Apparently a c— sock is not just a c— sock, it’s a c— and ball sock. So lesson learned. You’ve got to swoop down and sheathe the balls as well.”

O’Brien urged Peters to demonstrate to him just what a “c— sock” was supposed to do, and had Peters draw a diagram of the whole thing, though it was too inappropriate to reveal to the audience.

“It just looks like a mouse running into a net,” O’Brien said of Peters’ drawing.

Watch Peters relive the embarrassing experience below.