go behind someone'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.

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.
See also:
  • go behind (one's) back
  • go behind back
  • do something behind someone's back
  • behind (one's) back
  • behind back
  • behind somebody's back
  • behind someone's back
  • eggs is eggs
  • burner
  • backburner
References in periodicals archive
The temptation to go behind someone's back in love is strong, but several faces are watching you, so think before you act.
Stars; CLAIRE PETULENGRO'S WEEKLY PREDICTIONS
I also know what it's like to go behind someone's back and do the same thing.
Burden of infidelity; Should you come clean after cheating?
``I'm not the kind of person who would go behind someone's back. In an interview I was asked to comment on a number of band's outfits, including ours,and I commented on them.
Sweet and sour life of a Sugababe; Alun Prichard meets Keisha Buchanan of the Sugababes ahead of their Rhyl gig and finds her surprisingly weary of fame for one so young