I've made some super icky blunders when travelling because I know a smidgen of lots of languages [a misspent youth reading lots of books not meant for children...

] but not enough to really use a language well. Perhaps the one that spun me out the most was the little *rabbit droppings* that popped up in my coffee after I'd poured in the milk...apparently I'd bought yogurt & I'm still gobsmacked it was runny enough for me to mistake it for milk!
But the best was in Germany. Late @ nightish. We stopped @ a caff for milk & I refused to get out of the van. Leather jackets. Studs. Nose rings. Knuckle dusters. The man, who doesn't even try @ foreign languages but is 6', had to run the gauntlet. He tried in English & got the stink eye so...he mooed like a cow!

Cracked the place up but he got his milk.