Wait for me here. I'll only be a couple of minutes. I've just got to see a man about a horse.
(slang, idiomatic, euphemistic) A message signaling one needs to go missing for a short while, for any reason, without giving a real explanation.
Origin of see-a-man-about-a-horse
- The saying comes from the 1866 Dion Boucicault play, Flying Scud, in which a character knowingly breezes past a difficult situation saying, "Excuse me Mr. Quail, I can't stop; I've got to see a man about a dog."