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?