Q: Why do people say, ‘More tea, Vicar?’ when someone farts?
A: It’s a joke about the thin veneer of civilisation covering our animal nature.
In a semi-mythical English past, people, whether working-class or middle-class, called their front room, if they had one, the parlour.
The parlour was the best room, reserved for special occasions. One such occasion would be a visit by the vicar, the Church of England parish priest. The family would wear their Sunday-best clothes, and tea would be served using the best service.
The conversation would be somewhat strained, due to the status of the guest depending on a shared belief in a supernatural supreme being (a belief which would inevitably cause some doubt in the minds of all concerned, not least that of the vicar).
In this scenario, during an awkward pause in the conversation someone, perhaps nervously, lets rip a loud fart. To fill the even more awkward silence that follows, Mother brightly asks, “More tea, Vicar?“.