Originally Posted by Caber

Oh that brings back memories! Back in my own cabin crew days we used to play the same trick on new crew. The jackets they use for demos don't have the air canisters to inflate them since they are purely for demo use and hence crew routinely tug energetically at the tabs since nothing will happen.

That is of course unless you swap the jacket for a real one when they aren't looking Good test of composure to finish the demo properly