When Miss Manners observes people behaving rudely, she never steps in to correct them. She behaves politely to them, and then goes home and snickers about them afterward. That is what the well-bred person does.

Judith Martin (b. 1938) American author, journalist [a.k.a. Miss Manners]

Miss Manners’ Guide to Excruciatingly Correct Behavior (1982)