The next sentence: Un café con leche, por favor.
You actually ordered a coffee with jam but get an ordinary coffee. Annoyed, you insist on your coffee with jam (un café con – from the German “ungehalten”, “annoyed”, and “Konfitüre”, “jam”). Then you drop Lego bricks into the coffee instead of sugar – they come from Czechia, by the way (leche – from “Lego” and the German “Tschechien”). Finally you throw the Lego bricks out through the gate (por favor).