you'd be late for your own funeral
Said humorously to emphasize the fact that someone is always late or unpunctual. A: "Sorry, Sarah, I'm going to be about 15 minutes late." B: "Sheesh. You'd be late for your own funeral!" Rory Thompson, class started over an hour ago! You'd be late for your own funeral, young man!
Farlex Dictionary of Idioms. © 2024 Farlex, Inc, all rights reserved.