bite the hand that feed
恩将仇报;忘恩负义
口语·表示恩将仇报
英文释义
to harm or betray someone who has helped or supported you
例句
He criticized his boss publicly, which is like biting the hand that feeds him.
典故来源
源自字面'咬喂养自己的手',比喻伤害或背叛帮助自己的人。