[stab] {sb} in the back
1
to be disloyal and ungrateful to someone who has trusted or supported one
The idiom "stab someone in the back" has origins that date back centuries and are rooted in the idea of treachery and betrayal. The expression draws a vivid image of someone being betrayed by a close friend or ally who literally stabs them from behind, catching them off guard. It is used to describe an act of betrayal or treachery by someone who was previously considered a friend, ally, or trusted individual. It suggests that the betrayal was done secretly or behind the person's back, without their knowledge or awareness.
- I thought we were close friends, but he stabbed me in the back by spreading rumors about me.
- She promised to support my project, but then she stabbed me in the back by working against it behind my back.
- His business partner stabbed him in the back by stealing company secrets and starting a rival company.
- The political candidate claimed to be loyal to his party, but he stabbed them in the back by switching sides right before the election.
- Manfred tried to be nice to her, but he was stabbed in the back as well.