Quintening

verb: The act of intruding on other's conversations and pretending to know what they are talking about.

Greg : (Talking to his friend) Yeah, and it's always a pain in the ass when the teacher asks us to do essays.

Tom: (Replying) Especially when she makes us do something on Shakespeare.

(Hearing their conversation, Eric, A.K.A., "The Third Wheel", comes strolling along eager to join in on the discussion.)

Eric: Yeah! I know, right, guys?

(Greg and Tom proceed to ignore Eric, neglecting anything he says from that point on, due to the fact that Eric was quintening.)