This morning, I embarked on a lengthy transaction (don't ask) with the Chief lady (Pennaeth), during which the Deputy lady (Dirprwy) opened up a long narrative which I guessed might be a joke.
As the Deputy culminated, the Chief dissolved into helpless giggles for some time. Catching my eye, and remembering the precise level of my fluency in Welsh, she said, "Only I had to laugh, you see - she said something funny".