GIGGLING SHOP GIRLS

I made two female shop assistants giggle almost uncontrollably yesterday. I was buying some folders and went to the counter to pay. I know enough Thai to understand they were worrying about who was going to talk English to me, but of course I kept quiet. "You talk to him, no you talk to him, no it's your turn."
I kept quiet until I was handed my receipt and change, at which point I said, in my best Thai, "Thank you very much". "Wow, you speak Thai?" came the reply (in Thai). I replied "I speak a little" (in Thai) at which point the giggling started as they realised I had probably understood everything they had said.
Note to any of my staff reading my blog. I probably understand more Thai than you think!