A man about a horse

Yesterday I spotted a student who was absent from my just-finished class. When I asked him why he was gone, he responded:

"I had to see a man about a horse."

While I was impressed with his use of the American idiom, I wasn't quite sure why it took him an hour and forty minutes (the length of the class) to go to the bathroom. So I asked him to clarify.

"I had an appointment across town. Isn't that the right expression?"

For the next ten minutes I tried explaining the term as delicately as I could while also making sure that he really wasn't literally negotiating the purchase of any kind of livestock.

I was relieved that the discussion didn't end up like the one in Africa where I learned far too much when explaining "He knows where the bodies are buried."