A friend (who has a little Dutch and somewhat more Afrikaans) was once in a crowded train in Amsterdam. From the far end of the carriage his companion called to him that he'd found two vacant seats. My friend had already found somewhere to store his backpack, and called out (loudly, so as to be heard) something like "Ek komme, maar ek moet my eers aftrekke" ("I'm coming but I'm first going to unburden myself.") Unfortunately, 'aftrekke' in Dutch means 'masturbate'...