The scene when Morgan and Elle are discussing a twin's apparent psychic relation with the other twin. Bonus points to Hotch walking in, adding to the argument, and then getting straight to business.
Elle: You think Cheryl's a whack job because she claims she can feel her sister's anxiety?
Morgan: I never said whack job.
Reid: (walking in) Actually, there may be a psychological basis for it.
Morgan: Don't ask.
Reid: Reversed asymmetry monozygotic eggs split late, between 9 to 12 days. (Morgan shakes his head and smiles) The DNA matches right down to the very last stranded code, and there's sporadic documentation of shared physiological pain.
Morgan: And you believe it?
Reid: No, I'm just saying it's possible. I don't know everything, you know, despite the fact that you think that I do.
Morgan: I never said that. When have I ever said that?
Reid: Every day since I met you.
Elle: This morning at breakfast.
Hotch: (walking in) Yesterday, when he beat you at cards... um, we've got one minute.
Morgan: (As everyone walks away) Hasn't anyone heard of sarcasm?