Pride and Prejudice is an 1813 romantic novel of manners written by Jane Austen in which the protagonist discovers the difference between artificial manners presented as goodness and actual kindness.
In "Flush After Reading", Francine and Roger, using an ability of his to travel into books to hide from Stan, find themselves in Pride and Prejudice during the ball scene. After passing themselves off as Italian, Francine shares that the reason she is forced to go to the library to have a bowel movement is to keep Stan from discovering it was her that ruined a flight to Maui. Her discussion of diarrhea causes revulsion in some members and an interest in Italian food in others. While the latter set off to explore such conditions, the former chase Francine and Roger out of their book and into Sherlock Holmes.