In answer to the OP, I would be a little miffed. However, I would not wish to take the matter further and put it down to a bit of devilment.
The joke itself was not that bad. Trouble is, any humor would have drained out of it after about 10 seconds. After that, many passengers would have been feeling worry, apprehension and for some, even dread.
Hopefully this FO can stick to his day job and from now on leave the comedy bits to the cabin crew.