Holden, who doesn't have anything better to do, goes along with Stradlater to the bathroom to bug him while he (Stradlater) shaves and whistles. Badly.
Stradlater is a "secret slob"—he always looks put together and smells nice and all that jazz, but secret things, like his razor blade, are all crumby and filled with hair and rust. Ew.
Sure, Stradlater is cute, but mostly in the good-yearbook-photo way. (Wait, that's not enough?)
By the way, Stradlater needs a big favor. Eye roll. Hotshot people who are in love with themselves always need a big favor, Holden remarks (to us, not Stradlater).
Anyway, the big favor is that Stradlater needs Holden to write him a composition, but not a good one. Just a so-so one—not one with the commas all in the right place.
Eye roll #2. Holden hates it when people like Stradlater try to pretend the only reason they're bad at English essays is commas, when really they're just not good at, you know, English.
Anyway, Holden responds by doing a tap dance like you see in the movies, which he hates but gets a bang (his words) out of imitating.
He makes a point of telling us that Stradlater laughs.
Stradlater compliments the red hunting hat, but only so he can butter up Holden to ask him again to write his English composition (which has to describe something—anything).
Holden asks about a girl (Fitzgerald) that Stradlater was dating at one point. Stradlater says she's too old for Holden, and Holden responds by trying to put Stradlater in a half nelson.
Stradlater ("a very strong guy") pushes Holden ("a very weak guy") away.
Back to the girl-talk. Stradlater says his date's name is Jean Gallagher, and Holden "nearly [drops] dead."
See, her name isn't Jean—it's Jane, and Holden practically grew up next door to her.
Stradlater obviously knows nothing about this girl, but Holden goes on about how she used to dance ballet when she was little, and how, when they played checkers, she would never move her kings from the back row because "she […] liked the way they looked."
Holden admits that most people aren't interested in such details. Stradlater is obviously a member of that majority.
Stradlater gives Holden the go-ahead to run down and say hello, but instead Holden sticks around and talks about Jane's stepfather, an alcoholic who used to run around the house naked all the time.
Now Stradlater's interested.
Holden tells him to give his regards to Jane, but he knows Stradlater is the kind of guy that never does give regards, even when you make a point of asking him to.
What does Stradlater plan on doing with Jane on their date, anyway?
Not much—she only signed out of her dorm (at her own nearby boarding school) until 9:30pm.
Of course, this irritates Holden, who figures Stradlater is probably thinking that if Jane knew what a "sexy bastard" she was going on a date with, she probably would have signed out until three in the morning.
That’s… pretty much exactly what Stradlater is thinking. He reminds Holden about the essay and heads out of the bathroom.
Holden's actually relieved when Ackley comes back (pimple-picking and all), because it gives him something to do other than think about Stradlater potentially gettin' busy with Jane.