go behind (one's) back

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.
See also: back, behind, go
Farlex Dictionary of Idioms. © 2015 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!
See also: back, behind, go
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

go behind someone's back

If someone goes behind your back, they do something secretly or without your permission. Leonard, you haven't been completely open with me. You think I wouldn't know when you go behind my back? They go behind our backs, they withhold information, they talk down to us like idiots. Compare with do something behind someone's back.
See also: back, behind, go
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012
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