American plumbers

"… tell Petunia that very funny story about those American plumbers, Mr. Mason. She's been dying to hear…"

- Vernon Dursley to Mr. Mason, after a dinner party.

These American plumbers were the subject of an anecdote of Mr. Mason's, that Petunia Dursley was "dying to hear", in 1992.

Appearances

 * Harry Potter and the Chamber of Secrets