The “Home Alone” star recounts being mistaken for her former onscreen son’s actual mother.

Catherine O’Hara is not actually Macaulay Culkin’s mother, ya filthy animals.

The veteran actress, 69, reveals she was mistaken as the real mother of her Home Alone son, 43, at his Hollywood Walk of Fame ceremony back in December.

“Macaulay Culkin received a star on the Hollywood Walk of Fame, and he asked me to present it,” O’Hara recalls to Willie Geist on this weekend’s upcoming episode of Sunday TODAY.

“Out of the blue, he asked me. And my first reaction was, ‘Aww,'” she says. “I told my husband, ‘Aww.’

It just was the sweetest idea. But I didn’t know what it was going to be like, and it was just lovely and I’m so happy I got to be there and see him receive that. He seemed so happy. He’s got a lovely fiancée, two sweet kids.”

Catherine O'Hara and Macaulay Culkin

Catherine O’Hara with Macaulay Culkin at his Hollywood Walk of Fame ceremony.AMY SUSSMAN/GETTY

O’Hara recalls the mix-up occurring during the celebration’s photo-op.

“What was funny, when after you do the presentation, then they have the honoree come and stand before the unveil, the star. And then we all pose. We pose, pose, pose,” she says.

“His mother was not able to make it at that time. But we’re all posing, posing, posing. ‘Now Natasha, now so-and-so.

OK, now just you and the mother.’ And I walk away and he said, ‘Just with the mother.’ Yeah. No, with the mother.’ ‘I’m not — you know I’m not his real mother.’”

Culkin didn’t skip a beat with his response. “Then he puts his arm around [me], he goes, ‘Oh no, my mom wasn’t able to make it,’” O’Hara recalls. “Well then, I’m honored to be here. Thank you.”

Home Alone

Catherine O’Hara and Macaulay Culkin in ‘Home Alone’.20TH CENTURY FOX/KOBAL/SHUTTERSTOCK

At the teary reunion in December, O’Hara reflected on watching her onscreen son grow up through the years in her speech.

“This beautiful 10-year-old little boy was called a superstar, a moneymaker, one of the hottest leading young men in Hollywood,” she said.

“How does anyone survive that? I believe you’d have to possess a certain quality, a gift that dear John Hughes obviously recognized in Macaulay.”

O’Hara then thanked Culkin for including her, his “fake mom that left you home alone not once but twice,” to “share in this happy occasion.”