Unintended consequences

You're full after a lovely La Terrine de Courgettes au Coulis de Tomates Fraîches and a daunting but delicious Le Lapin en Cocotte when the waiter asks if you'd like dessert. Because you're spacing out a bit, and because he's lifting your empty plate, you assume he's asking if you're all finished. So you say, "Oui." Next thing you know you're ordering the tarte Tatin rather than extricate yourself from this unforeseen predicament. Good thing for the dessert compartment in the stomach. Perhaps French lessons are required after all.