off (someone or something) goes
Someone or something is departing. A: "The plane is taking off!" B: "Off we go on the adventure of a lifetime!" "Off she goes," Dan muttered, as he watched his baby girl drive away to begin her first semester of college.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
off someone or something goes
someone or something is leaving. (Said on the departure of someone or something.) It's time to leave. Off I go. Sally looked at the airplane taking off and said, "Off it goes."
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.