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 twos new movie, A Real Pain. Culkin stars in the film, while Stone produced the movie through her production company, Fruit Tree .

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

He also said theres 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.

Its nice because you go into a job and most of the time you dont really know anybody, Culkin said. But in this case, going in, Im like, Oh, OK, well at least that parts taken care of.