Chris Pratt got in big trouble with NBC on the “Parks and Recreation” set back during season two, when he surprised Amy Poheler by going fully naked during one of their scenes together.

Pratt described the incident to Seth Meyer during his appearance on “Late Night.”

"Andy was still dating Ann, or had been dating Ann and was like still in love with Ann, and she wanted him to come to the house," Pratt said, referring to his character and Rashida Jones’ character. "He got the signals crossed somehow and thought that she wanted him to come to the house naked and hook up. So I show up naked at the house. Leslie is there—Amy Poehler is there—to receive a naked Andy."

Pratt said he was given skin-colored briefs to wear during the scene, but after three or four takes he wasn’t "quite eliciting the response that I was hoping to from Amy.”

So he decided to show up for the next take totally naked.

"I went trou-down and the reaction was awesome," Pratt said. "It's the one they used."

But NBC was not happy with Pratt’s stunt and they sent him a letter about it.

"In the letter they did say, like, 'Hey listen, you can't do this, and also, probably don't go joke around about it. It's not a joking matter.' And it's not," he said.

Though he tried to keep a straight face while discussing the incident, Pratt struggled when he attempted to explain what he’d done wrong.

"You can't do that because...I don't know," he laughed. "Because you're not supposed to!"