We see hands filling up a "Big Quench" cup with non-trademarked slushie product. And then carrying the slushie through the halls of McKinley High while the soundtrack acapellas "Flight of the Bumblebees" at us. Which tells me that the slushie machine is in the high school. I want that franchise. Various students see the slushie cup and hurriedly jump out of the way. Mercedes sees it and screams out, "Mah weave!" Well, at least the bitch didn't pour beer in your weave. Rachel gasps with fear as the slushie approaches -- and then looks almost sad with rejection as it passes her by. Instead, the slushie is flung in the face of Finn. Finn grabs the slushinator and throws him against the wall, asking what the hell's going on. The slushinator is a hockey jock, who's decided that since Finn is now singing in Glee and has "insperminated the queen of the Chastity Ball," he's now below the hockey team on the social pyramid and is fair game for slushie attacks. Quinn and Finn are aghast at this development.
In the lounge, Will is spreading mayonnaise on his sandwich when Emma and Ken approach his table. They have a favor to ask. It seems that notwithstanding Emma's insistence that nobody know about their marriage, she has agreed to an actual wedding ceremony (as opposed to getting married by proxy, I suppose) on a beach in Hawaii (where nobody will know them). And she's also agreed to let Ken have a first (and, I imagine, last) dance. But the two of them can't decide on a song. Emma wants "I Could Have Danced All Night," (which Will gushes over like some big 'mo), while Ken wants "The Thong Song." So, taking an inspiration from two episodes ago, Ken and Emma are hoping Will can put together a mash-up of the two songs. Also, Emma needs dance lessons. Because Ken "had a monster case of athlete's foot a couple years back, had to get all [his] toenails removed, so she steps on [his] feet during the dance, [he'll] pass out." Gosh, I can't imagine why he's stayed single so long. Emma offers to pay Will for his time, but he wants to give them the lessons as a wedding present.
Music room. Quinn is sitting on Finn's lap and cleaning the slushie residue off his face. She's seriously worried that the two of them need to find a way to be cool again. Rachel is looking on forlornly, while Kurt and Mercedes predict that if Finn and Quinn got nailed with slushies, nobody in Glee is safe. Will enters and reminds the kids that sectionals are coming up. He noticed that they liked mash-ups, and he wants them to understand that sometimes two things that don't appear to go together can be great together (like bacon and chocolate, or football and Glee). So he hands out sheet music for "Bust A Move" and tells them their assignment is to find a good song to pair it with. But not before they sing the song by itself. None of the boys will volunteer to do the solo, so Will steps up to do it (but not before stripping down to a t-shirt). Which was okay once, but they have to stop revisiting this well. We all want to see Matthew Morrison sing and dance (and stripping down to his t-shirt is a good start), but Mr. Schuester can't keep singing lead for the Glee Club. Anyway, Mr. Schue sings and dances. And yes, at one point he does touch Quinn's face -- but it's more like a kindly uncle pinching her cheeks and less like a pervert copping a feel. So relax. Although even if he's not being pervy, it's super dorky for a teacher to be dancing like this. All the kids get into the singing and dancing except for Kurt. And when Will drags him to his feet and sings to him about some girl who's stacked, Kurt just mouths, "Oh my God," and walks away. And then Will does the splits right into the credits.