Facepalm sigh

The sigh you have when someone like mr. Alexander doesn't understand a very simple wordplay or something obvious.

Very closely related to facepalm, but expressed as a sigh.

Person 1: Do you know where the definition of the long drink esa-anssi comes from?
Alexander: hmm, I really have no idea
Person 2: *facepalm sigh...* It comes from esanssi.