The time I laughed really hard

The time I laughed really hard was at a Japanese restaurant with my friend. The waiter was talking to me and I couldn't understand a single thing he was saying. I just nodded my head and said ok to everything he said. But as soon as he turned away I yelled to my friend "What the **** did he say?" The waiter turned around and clearly understands what I said and he just gave an annoyed look and continued walking. My friend and me laughed so hard that we couldn't look at each other without laughing for at least 5 minutes. We just found it so funny from the waiter’s perspective because he was talking to a customer that he thought understood everything he was saying. And then he just hears the customer tell his friend that he couldn’t understand anything. That must have made the waiter feel so offended which my friend and I just found hilarious.