"The Rummy Affair of Old Biffy" is a short story by P. G. Wodehouse, and features the young gentleman Bertie Wooster and his valet Jeeves.

Also, Biffy intends to sell the country house he inherited; he has a potential customer, Sir Roderick Glossop, the so-called nerve specialist.

Not more than ten days later, Bertie sees a marriage announcement in The Times for Biffy and Honoria Glossop.

While the three eat lunch, Glossop says that Honoria asked Biffy to bring Bertie to the British Empire Exhibition.

And, before the crowd had time to realise what a wonderful bob's-worth it was getting in exchange for its entrance-fee, he was inside, engaging the girl in earnest conversation.

Jeeves asks what he means, and Bertie relates Biffy's story about forgetting Mabel's hotel and last name.

When Bertie told him the facts, Jeeves realized his mistake and directed Biffy to Mabel.

The story was illustrated by Arthur William Brown in the Saturday Evening Post, and by A. Wallis Mills in the Strand.

[4] "The Rummy Affair of Old Biffy" was included in the anthology The Shelter Book: A Gathering of Tales, Poems, Essays, Notes and Notions Arranged by Clemence Dane for Use in Shelters, Tubes, Basements and Cellars in War-Time, published in 1940 and edited by Clemence Dane.

[6] It was also collected in the anthology Classics of Humour, published in 1976 by Book Club Association and illustrated by Donald Room, along with "Comrade Bingo".