Rob “Boston Rob” Mariano admittedly wasn’t impressed by his “Traitors” co-star-turned-bestie Dylan Efron’s first “Dancing With the Stars” performance.

Efron’s debut performance on the current season of “DWTS” was a cha cha to Kelis’ iconic 2003 hit “Milkshake” with pro partner Daniela Karagach.

“After the first one, I was like, ‘We got to talk about the song choices,’” the “Survivor” legend tells Page Six’s “Virtual Reali-Tea” with a laugh while promoting his new Dunkin’ and Kahlúa collab, “It’s Kahlunkin’.” “Because that ‘Milkshake’ … [I] was not coming to the yard.”

Still, Mariano says he’s been in Efron’s corner — in his own tough-love kind of way. “I cut him down,” he jokes. “I said, ‘Listen, bro. The show’s not over ’til it’s over. Even after the dance, you look at the judges, ma

See Full Page