Adam Scott tells Kathryn Hahn he felt like 'such an a--hole' scolding her in their “Step Brothers” car scene

Scott played Hahn's jerk of a husband in the beloved 2008 Will Ferrell–John C. Reilly movie.

Adam Scott's character in the 2008 movie Step Brothers is such a jerk that the actor still feels bad about it.

He said so on Monday, when the Parks and Recreation and Severance star was a guest on Jimmy Kimmel Live, where actress Kathryn Hahn was filling in for the host. But first, the show ran a clip of the famous car scene, in which Scott's Derek and his wife Alice (Hahn) sing a song with their kids. Derek just won't or can't stop criticizing his wife. He says things like her singing is "the worst thing I've ever heard" and "$1,200 a week for voice lessons, and this is what I get?"

(See the movie clip and the interview with Scott at 4:45.)

Related: Jon Hamm and Dax Shepard recall losing Step Brothers role to Adam Scott: 'I was resentful'

"I remember feeling so terrible saying those, the lines about like that you're so flat and stuff, cause we did it all day," Scott said. "And I just felt like such an a--hole saying that over and over."

Hahn said that it was fine because she "became numb to it," which prompted Scott to joke that it was "much like" her character.

Alice is obviously unhappy in her marriage and soon begins a hilarious-to-watch affair with Derek's new step-brother Dale, played by John C. Reilly. Will Ferrell's Brennan is Dale's brother, although he's not happy about it.

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Turns out, Scott is the only actor in the scene who wasn't actually singing.

"You guys were singing live," he said of Hahn and the child actors who played their kids, Lurie Poston and Elizabeth Yozamp.

They agreed the kids were impressive, with Hahn calling them "terrifyingly good."

Related: The cast of Step Brothers: Where are they now?

"And you too," Scott said. "You were singing, like, you could — you can actually sing. I can't, like, carry a tune at all, so we had a guy, a ringer, singing for me. So I was lip-syncing to someone that was singing live right outside the windshield."

Hahn explained that they were in a studio with a green screen.

"And in my mind," she continued, "he was dressed as a boy band, like he had just walked out of a video."

Scott joked, "It was Justin Timberlake."

Read the original article on Entertainment Weekly.