Alan Cumming’s facial expressions got him in trouble during The Traitors season 3.

“I see when [contestants] write down who’s going to be banished,” Cumming, 60, said during his appearance on the Thursday, March 6, episode of The Tonight Show Starring Jimmy Fallon. “I can see, like, three or four of them sneakily behind their backs.”

Cumming continued to recall one moment during filming when he was convinced Boston Rob Mariano was about to get banished — but his face nearly gave it away when the Survivor alum’s name wasn’t written down.

“He clearly was a Traitor,” Cumming, who has hosted all three seasons of the Peacock series, explained. “There was so much evidence against him, and he managed somehow — with his sort of straight guy, mesmerizing ways — to stop them voting for him.”

When it came time for the banishment in episode 6, Cumming thought Boston Rob’s fate was sealed. The group ultimately voted out The Challenge alum Wes Bergmann instead.

“I thought, ‘They’re surely going to vote for Rob this time,’” Cumming recalled. “I saw somebody write Wes down and all of a sudden — I have a little thing in my ear — I hear this, ‘Alan, your face, your face, your face.’”

He added, “I rolled my eyes, and I couldn’t believe it.”

@fallontonight

Even Alan Cumming can’t believe some of the choices The Traitors contestants make at the round table 😭 #FallonTonight #TonightShow #AlanCumming #BostonRob #TheTraitorsUS #JimmyFallon

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Cumming added that the competition starts to feel similar to Lord of the Flies as it progresses.

“The pack mentality is really fascinating to watch,” he added. “I say that the show is Lord of the Flies with Botox.”

The emotional season 3 finale aired on Thursday, with — spoiler alert — Dylan Efron, Gabby Windey, Dolores Catania and Ivar Mountbatten winning the game together and splitting the prize money.

Cumming said during his Tonight Show appearance that it was “a curse” knowing who wins before viewers do.

“Obviously, I know because I was there,” the actor said. “We shot it last June and ever since … everyone says to me, ‘No spoilers,’ like that. The weight of nearly spoiling [is heavy].”

Cumming did admit to spoiling season 1 to comedian Pat Regan in 2023.

“He went, ‘I love reality shows. I hear Cirie from Survivor was on it and I went, ‘Oh, she wins,’” Cumming said through laughter. “His face fell. … This is about three years ago, and someone said recently, ‘He’s still talking about it.’ I’m so sorry, Pat.”

According to Cumming, there’s an extra “pressure” as the show’s host to keep the details under wraps.

“I’m the worst person to keep secrets,” he added.