The Mermaid’s Supper

Captain Lettice Wray had crossed three oceans, and she had excellent manners, which was the problem.
She anchored one calm evening near a rock where a mermaid sat combing her hair. They talked for an hour, about tides, and shipping, and the appalling state of the harbor at Port Marrow. It was the nicest conversation the captain had had in months.
“You must stay for supper,” said the mermaid.
“How kind,” said the captain, who had not eaten since noon. “What are we having?”
A silence on the water
The mermaid stopped combing. Somewhere below the boat, a large and thoughtful bubble rose to the surface. The gulls left. The mermaid smiled in a way that showed all of her teeth, and there were several more than the captain had expected.
“Well,” said the mermaid. “That depends. Who else is on your boat?”
How she got away
Captain Wray thanked her hostess, remembered an urgent appointment, and sailed away at a speed that remains a record for a vessel of that class. The ship’s cook, who had been asleep the whole time, never learned how close he came to being the main course.
The moral
Some questions are polite until you hear the answer. Never ask a mermaid what is for dinner, and never ask a salesman how he got the scar. And if your host is very pleased to have you, check whether you are the guest.
The captain’s warning now lives on a mug, right next to the kettle.