Stab in the back

Meaning: This common phrase refers to a friend or acquaintance betraying you for their own personal gain.

这个常用的短语指朋友或熟人因为个人的一己私利而背叛了你。

Example: Such a vicious lie could be nothing but a stab in the back.

这种恶毒的谎言简直是暗箭伤人。