When the Winter Ball King is first announced, Angus and Troy are so happy to hear it wasn't Rick that they both shout "All right!" and go for a high-five, not realizing that the nomination went to Angus himself. Cue hundreds of students craning their necks to stare at the two, as a mortified Troy yells "Holy SHIT!" and heads for the door.
"I don't know, man. What if he really can dance? All you can do is that... (imitates white-guy arm pumping dance) white thing."
As mean as the prank is, the underwear-up-the-flagpole bit actually is pretty funny, especially when Angus looks up and sees the boxers growing larger and larger in his mind until they're three times the size of the flag. And then Melissa walks by.
"That's what you call gettin' a slice of the ol' dick pie..."
The look on Angus' face when Melissa complains of her profuse sweating when she gets nervous. Then the spotlight shines on them, and Melissa immediately locks into smile mode while Angus squints awkwardly.
We actually get a subversion of this after one Crowning Moment of Heartwarming. A Running Gag in the film was for Angus to wake his Grandpa with a recording of "Reveille" every time he'd doze off. After Angus pours out his heart to Grandpa just before the wedding, the old man falls asleep again. It should have been funny, except that when Angus goes to put on "Reveille" this time, Grandpa doesn't wake up.
Angus and Troy disagree with Grandpa's choice of a purple, er, plum tuxedo for Angus.
Grandpa (to store clerk): Put it on him.
Angus: Put it on a hanger.
Troy: Put it on a dead guy and bury it.
When Angus talks about the butterflies in his stomach he gets when he sees Melissa:
Troy: You get a boner in your stomach?
When Troy sees his crush on stage at the assembly:
Troy: (whispering to Angus) I think I have an erection.
When Angus and Troy review a tape of Angus practicing slow dancing with Troy's inflatable sex doll:
(the sex doll is seated between Angus and Troy)
Troy: You're such a good dancer.
Troy: Not you!
Angus: Do you want to be alone?...(Beat) Can I borrow it?
Troy standing up to Rick's insults to Angus:
Rick: I'd lend you my shirt, but I'm afraid it might rip.
Troy: That's because it's cheap...like your mother.
Followed by Rick stuffing Troy wholesale into a small locker.