Burning the Sock

Noun; A fake inside joke made in order to test if someone is laughing at your inside jokes without knowing what they mean.

Verb; The act of putting someone through some form of unspoken test to indoctrinate them into a clique.

"Yikes, man that was crazy. I guess you could say you were really burning the sock on that one. *Everybody pretends to laugh, even John, who doesn't know what the joke means*"