Kieran Culkin reveals shocking words director said to him at age 6 that he’ll never forget

Kieran Culkin recalled a time a director made cruel comments to him as a kid.

Culkin has been in showbiz since he was a child, with the actor's first film role being alongside his brother Macauley Culkin in Home Alone.

Fast forward to today and he's now an Emmy Award and SAG Award-winning actor.

Most of his accolades are from his portrayal of Roman Roy in HBO's Succession, but Culkin also received critical acclaim for 2002 movie Igby Goes Down.

The 42-year-old recently reflected on his decades-long Hollywood career on the Smartless podcast, hosted by fellow actors Jason Bateman, Sean Hayes, and Will Arnett.

While speaking on the podcast, Culkin recalled a time he was filming a commercial when he was six years old.

"The concept was I'm standing in front of a chalkboard with chalk in my hand and I don't know how to solve the easy thing in front of me," he explained to Bateman, Hayes and Arnett.

"And the kids in the class are supposed to be calling me a dummy and stupid, all that."

Kieran Culkin recalled shooting a commercial at the age of 6 (Jo Hale/Getty Images)

The Scott Pilgrim star continued to share, as per PEOPLE: "I have a distinct memory of being there and the director going, 'Okay, action.' And he starts going, 'Dummy. Idiot. Stupid.'"

The actor fumed that he wasn't a 'f**king method' actor at the age of six and questioned the director's unconventional (and some-what cruel) way of working, adding: "I'm thinking like, ‘I get it. I'm 6. Stand here and look sad. I'm 6. What's wrong with you?"

Culkin now has children of his own and shares five-year-old daughter Kinsey and son Wilder, three, with his wife Jazz Charton.

While Home Alone is a Christmas classic that will be watched in many households across the globe this festive season, one place it won't be played is at Culkin's family home.

It's not because he dislikes the film, however, but because he's worried Wilder might be too young for it just yet.

The actor played Fuller McCallister in Home Alone (20th Century Studios)

"For the three-year-old, there’s the tarantula [and] there’s the guy at the end who said, ‘I’m gonna bite off all your fingers.’ That’s scary for a three-year-old," the father-of-two said at Gothams 34th Annual Film Awards in New York.

As well as 'scary' scenes, there's a heartbreaking moment between Kevin and his mom, played by Catherine O'Hara.

The Schitt's Creek favorite said it 'killed [her]' to film.

During her speech when her on-screen son Macauley received his star on the Walk of Fame last year, O'Hara recalled the moment Kevin says: "I don’t want to see you again for the rest of my life, and I don’t want to see anybody else, either."

Her character replies: "I hope you don’t mean that – you’d feel pretty sad if you woke up tomorrow morning and you didn’t have a family."

Then Kevin says he wouldn't feel sad about it, as his mom urged him to say it again then.

"I can't tell you how much that killed me," the Beetlejuice star of filming the scene. "I could not wrap my head around saying something so horrific to this beautiful child."