I was once in Poland visiting my gf at the time and we were sitting at the table with her family at the dinner table. Only her and her brother spoke english. We were making plans for the next day and I said "SUPA DUPA". Not knowing what it meant. Because in American English it is an old term that means "COOL, OKAY". Her mom turned around and started laughing. I said "Co". Then my gf told me what it meant.
Next day we were laughing about how I said SUPA DUPA at the dinner table and I said it sort of loud. And a girl heard me and started laughing.