I got very embarrased in Nashville once. In Oz you order a coffee "white"(with milk) or "black" no milk.
We went into a restaurant (Shoney's??) and I ordered two white coffees for my wife & myself. The African/American waitress glared at me, gave me a dirty look and said "You mean two coffees with cream"

Very embarrased, I apologised, explained, and after hearing my accent I think she understood it was an innocent faux paux.

I was very careful after that.


Cheers,
Keith