Derek Zoolander (Ben Stiller) wasn't supposed to ask this question a second time, but Stiller forgot the next line. He explained the entire story during an AMA on Reddit: "I literally was listening to what David Duchovny said . . . and I honestly forgot, I hadn't followed what he was saying, I said it again and got my lines wrong, and David (who's a very funny guy) improvised the 'are you serious? I just explained that.'"
"But Why Male Models?" Was Improvised