At some point she will have to figure out his name. 

"I'd love to," she says, and she'll be following his lead, right, it'll probably be fine that she's never done this before? 

Mysterious P. E. Boy is a very good dancer, which means that he can easily compensate for her lack of familiarity with fifties dancing. 

It also means that he can grab her hands and slide her between his legs.

If he can figure out how to do that without her having any idea what they're doing or indeed that this is a thing people do, holy shit that's really hot. 

Raine will keep dancing with Mysterious PE Person right up until he decides to stop. 

Unfortunately for her, the social convention is that you only dance for one song with each person!

When the song's over, he smiles at her and says, "Can I get you a drink?"

"Please." Social convention is terrible! 

He brings her a pina colada. "You look really pretty tonight."

(Lee is lurking near the edge of a social group compulsively eating sliced bananas and looking VERY uncomfortable.)

"Thank you," she says, and wow okay apparently she was hungry actually? weird. "You look great. — I mean, you always look great," probably this is a safe assumption to make? 

He laughs. "Thank you. --You're rather forward."

"Well, if it works," Raine says as if she were doing this on purpose and had any idea what the local flirting norms or indeed any flirting norms were. 

"I suppose you'll have all the boys lined up to ask you to dance," he says. "Forget always having a date on Saturday night, you always have one in the afternoon and then you have to hurry home to change."

"Mm. Sounds exhausting." She is not very subtly looking Asher up and down, even though probably he doesn't speak 21st century gay. 

"All you have to do is go steady with someone and then he'll take you for granted and not take you out at all and you'll have so much time for doing your Home Living homework."

"I'd like to think I'd have better taste than that." 

"Ah, you have high standards. Only the most devoted boyfriends for Raine. You're not going to go to Lover's Lane for anything less than a dinner and movie and flowers."

How about she just laughs and pretends to be as in on the joke as this person assumes that she in fact is! 

Someone calls "Anthony!" and he says "I should probably go see what that's about. Dance with you again later?"

Oh thank the gods she has his name. "Sounds great!" 

Three more guys ask her to dance! None of them are quite as good at dancing as Anthony, unfortunately. 

In between she can lurk on the edges of conversations with people who recognize her. The female-only conversations are mostly devoted to intense analysis of who's dancing with whom. The mixed-group conversations are devoted to football, flirting, complaining about classes, and movies. (No one seems interested in any aspect of movies other than the special effects, which are discussed with great enthusiasm.) 

She fakes her way into and through conversations, tries to learn as many people's names as she possibly can, and observes the flirting as closely as she can manage. 

The flirting is Very Gender. If you're a girl and you're interested in a guy, you twirl your hair and bite your lip and act shy; if you're a girl and you're not interested in a guy, you act determinedly oblivious to his intent until he goes away. If you're a guy and you're interested in a girl, you compliment her and tease her and brag in a way that is probably supposed to be subtle. 

The guys she dances with all flirt with her at least a little.

Yeah, okay, she probably could have guessed that. More importantly she can totally do that, or at least she can know what message exactly she's sending when she fails to do that. 

She joins in and flirts back, at least a little. 

Lee hangs out near the edge of conversations eating handfuls of chips so that no one asks him why he's not talking and staring longingly at Raine!

Eventually he works up the nerve to walk up to her and mumble something while staring at his feet.

She can glean from context cues what the thing he said probably was. 

"Yes." 

The fact that it is extremely rude to ever turn down a dance did not actually prevent him from being anxious that this might happen!

Lee's dancing strategy consists mostly of being extremely conscientious about not stepping on Raine's feet. This takes up all of his energy and leaves him with very little for the actual dancing part.