TV Trope: Funny Background Event

A female extra walks out of a building wiping her mouth. A male extra soon surreptitiously follows, zipping up his pants.

(3.17 Basic Lupine Urology)

TV Trope: Ironic Echo

Enemy #1: Welcome to Greendale, you’re already accepted?
Enemy #2: Losers.
[Two paintballs shoot through the Dan Harmon cameo poster and hit them - Annie, Abed & Shirley bust open the door]
Enemy #1: What the hell?
Annie: Welcome to Greendale.
Abed: You’re already dead.

(2.24 For A Few Paintballs More)