2. You were actually serious but decided what you said was actually very mean
3. You were actually serious but since that person took what you said offensively you cover it up by saying" just kidding"
4. When you try to confess to something and that person is either laughing at you in disbelief or just very angry you cover it up by saying just kidding
the first thought that comes in the head of an Emergency room physician when attending to a college girl who has just come in to the E.R. attempting to explain that the reason she has a cucumber broken off up in her twat is because she was making a salad in the buff, slipped, and fell on top of it.
You will say this when you question what is asked or told to you in the most extreme way possible.
Usually you would say "are you kidding?" in a subtle way if your calm but when you become full on angry, angrier that Goku...; ARE YOU FUCKING KIDDING ME?!?
basically...this can be said at any given time when someone asks you a favor, question, a "go do it" order.
Hey I forgot my bag at home can you drive 20 minutes over to drop it off
ARE YOU FUCKING KIDDING ME?
(Almost at the end of a Halo game, Iron being on..and everyone dies) ARE YOU FUCKING KIDDING ME?
(Power goes out when you are downloading super important shit) ARE YOU FUCKING KIDDING ME?