The Rules of Attraction (2002)

Continuity mistake: When Lauren and Lara share cocaine in their dorm room, Lara's face starts out clean. After a few quick cuts between the girls, her nose is dusted with white powder. There is another quick cut to Lauren and back to Lara, and the powder is gone, before she has had a chance to wipe it off or move.

Lara: How do I look?
Lauren: You look kind of skinny, actually.
Lara: Skinny, really? Bulimic skinny or anorexic skinny?
Lauren: What's the difference?
Lara: Bulimic skinny passes for healthy, except your teeth rot. But my teeth aren't rotting, so.
Lauren: So you look bulimic skinny.

Trivia: When Sean Bateman answers the payphone call from Paul, he asks if it's Patrick calling. Patrick Bateman was a character from American Psycho, which was made by the same production company. Also, Patrick Bateman was Sean's brother in the novel.