The hit drama picked up the award for Outstanding Performance By an Ensemble -- Drama Series and when the win was announced, Culkin, 39, and Smith-Cameron, 64, who were sitting next to each other at the Barker Hangar in Santa Monica, California, stood up and locked lips.
The candid moment played into their characters' ongoing flirtation on the series.
After the win, ET's Nischelle Turner spoke with the cast, and Culkin admitted that they were not anticipating taking home the statue.
"It feels like they're going to say Squid Game, that's what it feels like," Culkin quipped of hearing their show called for the win.
Though the cast is remaining tight-lipped about any season 4 plot lines, Culkin did speak with ET on the red carpet prior to the award show about the future of Succession, and the fan prediction that it might be coming to a close after season 4.
"Maybe, I don't know. I have no idea," he admitted to ET. "I think they go season by season. I know they went into the writer's room a couple weeks ago. If I were to guess, my guess is they probably don't know themselves."
Despite not knowing the writers' intentions, Culkin said he's ready for more seasons.
"As a fan of the show, I would like to see more. I would like to see at least two more seasons. That's just as a fan. But I also trust [creator] Jesse [Armstrong], and if he feels it's time to stop, he's gonna be right."
The 2022 Screen Actors Guild Awards aired live on TNT and TBS on Sunday, Feb. 27 at 8 p.m. ET/5 p.m. PT. Stay tuned to ETonline.com for complete coverage of the 2022 awards season.