Miss Manners: What’s the best way to handle being stood up for social plans?

A reader seeks guidance from Miss Manners regarding friends who frequently cancel social plans at the last minute, sometimes to prioritize other people. The individual aims to address these recurring situations while remaining polite. Advice is provided by Judith Martin, Nicholas Ivor Martin, and Jacobina Martin, focusing on the best methods to handle being stood up and managing social disappointments effectively while maintaining etiquette and personal boundaries within these friendship dynamics.