Music room. Lauren enters with her new besties Santana and Brittany. Really? Anyway, Lauren's complaining about her inability to find a single dress in her size that's suitable for prom. When they hear Lauren threaten to make her own dress, they all warn her that making your own prom dress can only lead to heartbreak (plus leading to Jon Cryer stalking you). Quinn in particular tells her that prom is a once-in-a-lifetime event that she'll remember forever, so if she doesn't get it exactly right she might as well kill herself. I mean, that's what I took away from Quinn's speech. Mercedes is happy that she doesn't have to worry about prom dresses, since she's not going. Which is due to the fact that nobody asked her. And then Will starts the rehearsal or the class or whatever it is by writing the word "prom" on the whiteboard. Demonstrating that he's not the stupidest of the Glee Club dim bulbs, Sam worries that they'll be performing songs about prom. Are there many of those? Or any? Will, of course, is just telling them that they'll be singing at prom. He tells them that he knows they'll all really want to be dancing with their dates instead of performing, so he'll stagger the performances so that everybody has some down time. That upsets Mercedes enough that she does a Rachel and flounces out of the room. Quinn tells Will that Mercedes is upset over her dateless status. Brit-Brit: "So? I don't have a date. I'm just going to dance. And then all your dates are gonna ignore you and come dance with me. So, your dates are really my dates." Rachel goes after Mercedes.
In the hall, Rachel tries to comfort Mercedes by pointing out her own lack of a date. But Mercedes just wants to feel like a pretty, pretty princess for once in her life. She needs to stop watching Cinderella and go watch Tangled. And then she can grow her hair out and kick some ass. In any case, Rachel has an idea.
Breadstix. Kurt and Blaine are sitting at a booth. Kurt, holding Blaine's hand: "Blaine Warbler -- will you go to junior prom with me?" Blaine seems to have some trouble wrapping his head around the very idea of prom, just repeating the word a couple of times. Kurt: "What about prom, Blaine?" It turns out that at his old school, Blaine invited a guy to a dance and the two of them got beat up afterwards by a trio of bullies. So he's a little shell-shocked, promwise. Kurt makes it clear that they don't have to go if it will make Blaine uncomfortable. But Blaine is really crazy about Kurt, so he'll go.