Split screen: "You guys slept together last night!?" The audience should be on a third screen saying it, too. Everyone agrees it's a terrible idea. Barney announces a "relapse five." You give a high-five, feel awkward, and then high-five again. I like it better when The Todd does these. Lily recaps their recent events of Robin's dating life while she throws in non-sequiturs like, "That is a truth-fact" and "Ka-Blammo." Lily asks why Robin is trying to destroy American Thanksgiving. She says the night before was a fluke. Lily asks if they at least talked about it. Side-whoosh to Robin and Ted getting dressed after sex and awkwardly not talking about it. Back in the present, Robin wants to talk about it. Ted really doesn't. He tries to say that some mushrooms are carnivorous. Probably. Not. They get into an argument about who started the sex. Ted says she "leaned into it" like a Little Leaguer. Ted drops some mushrooms, breaking a dish. "Oh, no! The slappetizers," Marshall says to a rattled Barney. Lily is fed up. She throws Ted and Robin in Ted's room to sort this out. Marshall offers to calm Lily down by putting something on the computer. She thinks it's music, but it's actually the Slap Bet Countdown site. It says 2 hours 45 minutes 20 seconds, but Marshall says, "Look at that! That means we're in the final hour of the countdown!" Barney says he's not scared, but his cheek is twitching. Marshall thinks it's happening because Future Marshall slapped Future Barney so hard that it caused a reverberation in the time/slap continuum. Barney cracks. He cries that he doesn't want to get slapped again. It hurt a lot last time. He doesn't like it one bit. Barney confesses that Marshall made it so much worse with the countdown. He can't sleep, he can't eat, he's lost 10 pounds. He says his suits are wearing him. Barney moves to leave. He says Marshall can slap his face, but he shouldn't be able to slap his mind. Mind-slapping! Marshall doesn't want Barney to go. It's Slapsgiving! Lily yells that it's Thanksgiving. She says it's their first one as grown-up married people. She's mad at everyone. As Slap Bet Commissioner, she rules that there are no slaps on Thanksgiving. "In your face!" Barney yells, "not my face, your face!" Bob walks in, saying hi to his "dudes." Lily tells Marshall her word is final and tells him to go mash some potatoes. Bob brought a bunch of Jell-O shots. "We's gon' get silly, bitches!" he announces. Barney gives him a high-five.