Hosts Kathie Lee Gifford and Hoda Kotb busted the pair breaking the rules, discussing secret answers and writing them down after time was called, declaring at the end they had "cheated through the whole thing".
The "Fuller House" actresses were taking part in a TV Duo Showdown segment, which pits famous television pairs against each other, including the hosts, and "Growing Pains" stars Kirk Cameron and Tracey Gold.
Despite Bure and Sweetin being most famously part of a trio of sisters, their on-screen sibling was at that very moment in Boston awaiting her appearance in federal court instead.
Before the fun game got underway, Hoda asked the girls if they had anything to say about Loughlin's predicament.
"It's too personal to us and we would never want to talk about someone that's such a dear and close friend," Bure said. "I've already said that we are family and we stand by each other and pray for each other and we'll always be there for each other."
Meanwhile, back to the alleged game show cheating.
Guest game show host Meredith Viera asked questions about each pairing, and the players had to guess their partners' answers without looking; despite the lighthearted nature of the segment, some whispering, erasing and furious re-scribbling of answers among Bure and Sweetin drew some serious side-eye from Kathie Lee.
Even when the camera cut to them after answers had been submitted for the final question, the duo were still writing away.
"Uh-uh, too late," Hoda interjected, while Kathie Lee could be heard protesting off camera: "They were talking the entire time."
Nevertheless, after "guessing" the correct answers, the Fuller House pairing were declared the winners by Viera, prompting Gifford to shout: "Because they cheated through the whole thing!"
They were awarded a pair of "Best Friend" sweatshirts, which they delightedly posed with, which in turn served as a stark closing reminder that "being there for each other" does not necessarily include physically in court.