stab in the back
背后刺一刀
口語·表達背叛或欺騙
英文釋義
to betray or deceive someone, especially in a sneaky or underhanded way
例句
I can't believe my best friend stabbed me in the back by spreading rumors about me at work.
典故來源
源自戰場上的背刺行為,比喻暗中背叛或出賣信任自己的人。