On Monday, Smith-Cameron first revealed the funny incident with her Twitter followers, joking that Culkin "had it coming." She also posted a photo of herself and Culkin, who clearly had some sort of liquid on his gray t-shirt.
Then, while appearing on Wednesday's episode of "The Late Show with Stephen Colbert," Culkin -- who came straight from the "Succession" set and was wearing clothes from his character Roman Roy's wardrobe -- recalled how it all went down, revealing what he did that ultimately led to Smith-Cameron throwing a drink at him.
According to the 39-year-old actor, it all began earlier on Monday after Smith-Cameron, 64, was feeling "insecure" after a table read as the script apparently included Culkin's character, Roman, making a "joke" about the age of Smith-Cameron's character, Gerri.
"We just finished doing a table read for, like, the fourth episode, and she was, like, a little upset. She goes, 'You have a joke about my old age and there's always so many jokes about how old I am,'" Culkin recalled, noting how the Emmy-winning series can often be "pretty brutal about making fun of everybody."
Then, later at a cast dinner, their co-star, Sarah Snook, pointed out how a man's physical features can change as they age. However, Culkin used Snook's words to tease Smith-Cameron.
"You know, she was insecure about being old, and later on we're having a dinner, and Sarah Snook is saying, she's like, 'You know, men's ears and noses never stop growing, so as they get older, they have long ears.' I said, 'You sure that's just men? And J. goes -- she goes, 'Why are you pointing at me? What? What?,'" he said, imitating Smith-Cameron. "And I was like, 'No, no, no. I'm just saying. You have long ears. Were they always that way? Or were they…' Still I don’t have the drink in my face. That's not -- That's early on in the dinner."
Culkin said he continued to push Smith-Cameron's buttons.
"Later on, the restaurant is getting more and more full, so it gets harder for her to hear, so she just keeps having to ask, 'What’s funny? Why are they laughing? What did he say?'" he told Colbert. "And I was like, ‘You got all that ear, and you can’t hear?’ Still no drink in my face. Still no drink in my face!"
However, after one final joke from Culkin, Smith-Cameron appeared to have had enough.
"We get the check and everybody's getting ready to go," Culkin shared. "She goes, 'What’s happening? What are we doing?'"
"And I take her hand, I go," he added, bringing his voice up a few volumes. "'We're going now. We're all going home. It's 8 o'clock. Thank you so much for staying up late. We appreciate..."
At that moment, Smith-Cameron threw the drink in Culkin's face.
As Colbert's audience roared with laughter, Culkin admitted, "I deserved it," to which Colbert quipped, "You're lucky it was a drink, not a steak knife."
Meanwhile, on Thursday, Smith-Cameron hilariously trolled her co-star on Twitter.
Alongside a clip from Culkin's appearance on the late-night talk show, she wrote, "i believe, btw, that i have normal sized ears."
In a follow-up tweet, the Emmy nominee tagged Colbert's personal Twitter account as well as "The Late Show's" and wrote, "bring us BOTH on so I can tease him about his 'back to school hair cut' and his 'day-camp shirts set' he was wearing that evening, which I am generally too nice to ridicule him about. (only don't allow him beverages)."
"I could have offered to cut his steak for him, but I REFRAINED," Smith-Cameron joked in another tweet.