For Macaulay Culkin, John Candy was more than a co-star.Culkin, who appeared alongside Candy in 1989's "Uncle Buck" and then again in 1990's "Home Alone," spoke about the late comedic actor in a new documentary, revealing that he was one of the few people in Hollywood who checked in on him about his "monster" of a father, Christopher "Kit" Culkin."I think he always had that really great instinct," Culkin said in "John Candy: I Like Me," which premiered Thursday at the Toronto International Film Festival.‘HOME ALONE’ STAR MACAULAY CULKIN HASN'T SPOKEN TO HIS ‘NARCISSISTIC’ DAD IN OVER 30 YEARS"I think he saw," he explained, per People. "Listen, even before the wave crested and the ‘Home Alone’ stuff was happening, it was not hard to see how difficult my father was. It was no secret. He was already a monster."Culkin has been open about the struggles he faced growing up in his father's home – in a 2018 interview with Marc Maron, he called him a "bad man," claiming that he was "abusive, physically and mentally."The former child star has also said that his father hid his earnings from him, so much that he felt the need to remove both of his parents from his trust in 1995 to protect it.In the Candy documentary, Culkin said that while his father was a "monster" before he became a successful actor, "All of a sudden, the fame and the money came, and he became an infamous monster. He was already not a good guy. I think John was looking a little side-eyed, like, 'Is everything alright over there? You doing good? Good day? Everything's alright? Everything good at home? Alright.'"He said that Candy's acknowledgment of his father's behavior was "a testament to the kind of man he was," and said that the older star "was just looking out" for him."It doesn't happen that often," Culkin said of his "paternal" co-star's choice to check in on him. "It actually happened less as time went on. I wish I got more of that in my life. It's important that I remember that. I remember John caring when not a lot of people did."LIKE WHAT YOU’RE READING? CLICK HERE FOR MORE ENTERTAINMENT NEWSHe added that while many stars "don't know how or don't like to work with kids," Candy "was always really kind, and really good" with him and Gaby Hoffmann, who starred alongside the two in "Uncle Buck."Candy was a beloved comedic actor throughout the ‘80s and into the early ’90s. In addition to the films he did with Culkin, he appeared in films like "The Great Outdoors" and "Planes, Trains & Automobiles."Candy died of a heart attack in 1994. He was 43.Earlier this year, Culkin admitted that he hasn't spoken to his father in over 30 years."Oh, he deserves it too," he said during an appearance on Kate and Oliver Hudson's "Sibling Revelry" podcast. Yeah. He's a man who, he had seven kids, and now he has four grandkids. Yeah. And, none of them want anything to do with him."CLICK HERE TO SIGN UP FOR THE ENTERTAINMENT NEWSLETTERTwo of those grandchildren are Culkin's – he shares two sons, Dakota and Carson, with his partner, actress Brenda Song."Now that I have kids of my own, it's like, you know, it kicks up some dust," he said. "I kinda go, you know, like, I can't believe he was like that. He had all these lovely kids. It's crazy."