handshake prank

I know it has happened to me, and probably to you, too. Someone is waving to somebody directly behind you, and you think the person is waving to you. And, even though you have no idea who the person is, you wave to be friendly, only to find out the person was waving to the person behind you the whole time. You think, "Well, that was awkward." This video shoes another awkward moment. When