What’s the funniest thing a friend from abroad has done and said in the uk?

A friend from Spain was visiting this summer, and I wanted to give him the most culturally British experience. I took him to greggs where he got a pasty and a Fanta. Before he paid he asked the woman behind the counter “do you have a glass with some ice?” I couldn’t help laughing and it was something my British friends found funny too. What’s the funniest thing a foreign friend has done when visiting?