Inside Joke and you're on the Outside. Used on someone looking for an explanation of an inside joke. Usually leads to further confusion, as it is often use as an inside joke of its own.
Guy: Jane sure is bootylicious.
Guy 2: That thing is like a watermelon!
Girl: What are you guys talking about?
Guy: I J and you're on the O.
Guy 2: That thing is like a watermelon!
Girl: What are you guys talking about?
Guy: I J and you're on the O.
by StegDizzleG July 29, 2011