"I said, close your dog."
I, with the practiced calm of continuous confusion, look around for a dog. I don't own a dog, but maybe there is one about I could… close. Alas, can't even find a cat.
"I'm sorry, what?"
Well, there you have it, my zipper is wide open. I close it up and thank the nice old man. Later I will find that he was actually telling me to "close my chain". That would be the slag here for zipper (chain and dog sound remarkably similar in French). I'm not sure if that would have really helped, but I looked up the actual French word for zipper and it turns out to be "fermeture à glissière". That basically means "sliding closure" and would have left me equally baffled.