An Abbreviation Abberation

(I’ve just finished making a sandwich for a customer. I am new at this, so he double-checks what I do.)

Customer: “Did you forget anything?”

Me: “No, sir.”

Customer: “Are you sure? You remembered the cucumbers and turkey?”

Me: “Yes.”

Customer: “And the lettuce?”

Me: “And the tomatoes, pickles, mustard, and mayo, sir. It’s written on the—”

Customer: “Mayo? What the h*** is that? And you left out the mayonnaise! Why did you do that?”

Me: “But, that’s what I said.”

Customer: “No! You said mayo! That’s not what I wanted!”

Me: “I put in mayonnaise. Mayo is just an abbreviation.”

Customer: “Abbreviation? What’s that, some kind of fruit?”