I used to work with a Ukranian coworker, who had so little of an accent that I often forgot he was not a native English speaker.
One time during a meeting, I mentioned "there's more than one way to skin a cat" and I can still picture the horrified look on his face when he processed what I just said.
I used to hang about with this Italian couple, and I remember smoking outside a pub with them years ago when I sort of offhandedly said "it's like the difference between shit and sheet", and one said "what's the difference?" so of course I spent a good ten minutes trying to demonstrate the difference by saying "shit" and "sheet" over and over with them trying to copy me. The bouncer loved it.
We have a climate chamber ("Klima-Kammer in German) at work for testing products, and my Ukrainian coworker kept referring to it as the "camera", I thought that was funny.