My supervisor was talking about a colleague, who, like me, is Italian. My supervisor doesn’t speak Italian (except for maybe a few basic words).
My supervisor kept on stressing the wrong syllable in the first name of the colleague. Nothing wrong with that, although it’s a very common name that is not so hard to pronounce correctly.
I told my supervisor the correct stress of the name.
He stared at me, then went on with his version. To this day (four years later) he still cannot accept that I speak my native language better than he does.