False friends are sometimes talked about by enemies.
Long, long ago, I was sitting in an aircraft listening to a language I don’t work with anymore, having almost totally lost my speaking ability, while retaining some reading ability, in that language. I heard the following, spoken by someone in another aircraft.
[Я] выпустил шланг.
When I was growing up in the US I was exposed (linguistically, anyway) to the last word in that sentence (shlang) but only in its borrowed meaning in Yiddish slang as spoken in the US.
That meaning is generally understood (although frequently spelled differently) in the US across ethnic and language boundaries, and I was rather surprised that someone in a military aircraft would announce that he had let it out. I would’ve thought that he would have kept it to himself, so to speak.
I was young and inexperienced, and in spite of my high grades in Russian, I did not understand the borrowed sense of the word in Russian (hose). Before I realized what was being talked about, the revelation of its being let out caused me to chuckle.
A colleague sitting next to me in our aircraft didn’t realize what was going on; I was listening (it then occurred to me) to an air-to-air refueling exercise, and he was listening to something else.
And now back to regular programming.