go behind (one's) back
To do something in one's absence. The phrase typically suggests wrongdoing or deceit. I can't believe you went behind my back and gossiped about me! Tom will be upset that we've gone behind his back and made the decision. I know you're desperate to get this deal done, but I wouldn't go behind the Speaker's back to do it.
Farlex Dictionary of Idioms. © 2024 Farlex, Inc, all rights reserved.
go behind someone's back
1. Lit. to move behind someone; to locate oneself at someone's back. The mugger went behind my back and put a gun to my spine. Bob went behind my back and pushed me through the opening.
2. Fig. to do something that is kept a secret from someone affected by it. I hate to go behind her back, but she makes so much trouble about things like this. Please don't try to go behind my back again!
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.