Director - Ben Stiller

In this scene involving former hand model J.P. Prewitt (David Duchovny) and the dimwitted male model Derek Zoolander (Ben Stiller), Prewitt - a conspiracy theorist - explains how the fashion industry has been behind every high profile political assassination of the last hundred years.
Zoolander asks, "Why male models?" Prewitt answers with a lengthy explanation, after which Zoolander responds again, "Why male models?" Stiller forgot his original line and just repeated his previous line instead. This prompted Duchovny to ad-lib his response "Are you kidding? I just told you like a minute ago."
The scene ends up reinforcing the movie's narrative of the brainless male model stereotype and Stiller turned a gaffe into one of the funniest parts of the film.