1. A polite, somewhat rhetorical inquiry to a guest who is you leaving a social meeting sooner than expected. A: "Well, thank you for dinner, but I really must get back to the house." B: "Aw, you leaving so soon? We were going to play a few board games after dessert!"

2. By extension, an ironic phrase said to someone who is trying to escape a dangerous or threatening situation. Used chiefly in fiction. "Are you leaving so soon?" the killer said to the detective, as he lunged at her with a knife.