Home Alone star Catherine O'Hara has revealed there is one line in the iconic Christmas film that she found so "horrific" she struggled to say it to Macaulay Culkin.
The iconic 1990 film has become a classic and is a staple for many people's Christmas viewing, with its follow-up - 1992's Home Alone 2: Lost In New York, being just as much of a fan favorite.
The first film sees Kevin McCallister - played by Culkin - defending his home in Chicago from burglars after being accidentally left behind by his family, who traveled to Paris for their holiday vacation.
While the movie may have shot Culkin to fame and remains one of his most notable roles, O'Hara - who played Kevin's mom Kate - revealed the one line that she found difficult to say during shooting.
The pair reunited this past week as Culkin was honored with a star on the Hollywood Walk of Fame, inviting O'Hara to be one of the speakers.
The actor shared a heartfelt speech of his own, in which he paid tribute to his wife Brenda Song, and left fans stunned at hearing his 'adult' voice at the same time, which was not what people were expecting.
Speaking about the Chris Columbus-directed movie in her own speech at the star ceremony, O'Hara revealed the line that she found extremely hard to say to a young Culkin.
At the start of the movie, Kevin falls out with his family the night before they are due to fly to Paris for their Christmas vacation.
As a result, his mother sends him to sleep in the attic as punishment, telling him he doesn't want to see him "for the rest of the night", to which Kevin replies: "I don’t want to see you again for the rest of my life, and I don’t want to see anybody else, either."
His mom then responds: "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."
O'Hara admitted that the line that followed was one she found horrific, explaining to the crowd: "The scene where I had to drag him upstairs to sleep in the attic 'cause he’d misbehaved, he’s mouthing off about the family and I say, 'Well, you’d be pretty sad if you woke up tomorrow morning and you had no family,' and he says, 'No, I wouldn’t.' And I was supposed to say, 'Then say it again - maybe it’ll happen.'"
The Schitt's Creek actress continued: "I can’t tell you how much that killed me – I could not wrap my head around saying something so horrific to this beautiful child."
She then joked: "Of course, I was not yet a mother at the time and I had no idea the kind of things would come out of my own mouth with my own two sons."
O'Hara also praised Culkin for his strength at dealing with such incredible child stardom at such a young age, adding: "This beautiful 10-year-old little boy was called a superstar, a moneymaker, one of the hottest leading young men in Hollywood by the world over.
"How does anyone survive that? I believe you’d have to possess a certain quality, a gift, that dear John Hughes [who wrote Home Alone] obviously recognized in you Macaulay, your sense of humor.
"It’s a sign of intelligence in a child and a key to surviving life at any age. From what I see, you have brought that sense of sweet yet twisted, yet totally relatable, sense of humor to everything you have chosen to do since Home Alone."
O'Hara also credited the global success of the movie and its enduring popularity on Culkin's talent and magnetism in the role, telling the crowd: "Home Alone was, is, and always will be a beloved global sensation. The reason families all over the world can’t let a year go by without watching and loving Home Alone together is because of Macaulay Culkin.
"Yes, he had a most excellent script and a wonderful director. But it is Macaulay’s perfect performance as Kevin McCallister that gave us that little every boy on an extraordinary adventure."
She got choked up as she told him: "I know you worked really hard, I know you did, but you made acting look like the most natural thing in the world to do. It was really as if we’d ambushed this real little boy named Kevin to make a movie and he just went along with it for the fun of it."