Kieran Culkin has no qualms about working with a famous ex.

The “Succession” actor recently joined forces with his former girlfriend, Emma Stone, for the two’s new movie, “A Real Pain.” Culkin stars in the film, while Stone produced the movie through her production company, Fruit Tree.

“She’s great,” Culkin said of Stone during an interview with E! News’ “The Rundown” at this year’s Sundance Film Festival, where “A Real Pain” made its premiere. “She’s a really wonderful person.”

He also said there’s an unexpected benefit to working with someone you know so well on a project like a movie, where you can face a lot of unknowns.

“It’s nice because you go into a job and most of the time you don’t really know anybody,” Culkin said. “But in this case, going in, I’m like, ‘Oh, OK, well at least that part’s taken care of.’”

Culkin told Rolling Stone in an interview earlier this month that he finds it “funny” to think of Stone as his “ex.”

“To me, she’s just a really good friend of mine and my wife’s. She’s lovely and great,” he said of the actor, whom he dated from 2010 to 2011.

“I met her when the rocket took off. I was right at the beginning of the huge launch; I got to watch all that firsthand,” Culkin added. “And I remember at the time that I was a little more aware of the direction she was going than she was. She would be like, ‘Oh my god! I just got this opportunity…’ And I’d be like, ‘Yeah, but of course you did! Everyone loves you and you’re great.’”

Stone has since married Dave McCary, a comedian and director who used to work for “Saturday Night Live,” which is where the two met. The couple shares one child together, a daughter named Louise Jean McCary, who was born in March 2021.

Culkin married his wife, Jazz Charton, in 2013. They have two children together: daughter Kinsey Sioux and son Wilder Wolf.