Ackley is the annoying boy next door to Holden Caulfied and his roommate Stradlater at Pencey. One irritating habit of his is barging into the room and picking up things that belong to Holden, then asking inane questions about them. For example, he would pick up Holden's personal things from the desk or chiffonier and then not return to that spot, but toss them onto the bed or the other piece of furniture that they had not been resting after asking a question about it, but not really caring about the answer. He always asks about Holden's roommate, too, as though he were envious of him since he has no ownership in which anyone is interested. And so, Ackley tosses Holden's things away in pretended disdain for them.
Whereas Ackley rarely leaves the dormitory,"sort of a nasty guy" with seemingly no friends, Stradlater appears the conventional "big man on campus" who assumes that others are around to serve him. Curiously, Holden assumes a role almost like that of Ackley as he sits on the wash bowl and observes Stradlater, who walks around in his towel because "he knows he has a good build," shave. Holden calls Stradlater "very ironical" rather than himself in the scene in the bathroom when Stradlater asks Holden to write an essay for him.
"A secret slob" who looks neat on the exterior, Stradlater has a messy razor with which he shaves, but he goes over his face twice and he combs his hair several times. When Holden feels like wrestling around, Stradlater tells him to stop it because he has a date; and, ironically, it is a date with a former friend and neighbor of Holden's, Jane Gallagher. Hearing this, Holden becomes jealous, for he had been fond of Jane; he continues to talk about Jane, irritating Stradlater. After following him back into the room, Holden asks him not to tell Jane that he flunked out of Pencey.
That was one good thing about Stradlater. You didn't have to explain every... little thing with him, the way you had to do with Ackley. Mostly, I guess, because he wasn't too interested. That's really why. Ackley, it was different. Ackley was a very nosy bastard.
Not only is Stradlater going out with Jane and having him write his composition, but he borrows Holden's new sweater. He knows how to exploit people whereas Ackley is a social nuisance and inferior who, in his envy, talks of his hatred for the others. When he returns to Holden's room after Stradlater departs, Holden is glad to see Ackley because "he took my mind off the other stuff," the fact that Holden burns with jealousy that Stradlater has a date with Jane. At least with Ackley, Holden can be superior to him.