To joke on someone, to pull a
fast one; to be mischevious and devious in intent and nature; to fool someone or lead them on thinking one
thing, only to have them unpleasantly surprised about the
true result
Guy puts in work all
night for this girl at a
party. As they go upstairs and get ready to have sex, the girl passes out before
anything happens. The guy's response, SHANANAGAINS.