bite the hand that feeds you
字面上的意思是不要咬给你喂吃的东西的手,当别人好心照顾你,甚至亲手把饭喂到你嘴里,而你却把那只手给咬了,这不就是在恩将仇报嘛。
to hurt someone who helps you; to go against the person or thing that provides something necessary
伤害帮助你的人;反对给你提供必要东西的人或物
The college gave me a scholarship, so I shouldn't bite the hand that feeds me and criticize its hiring policies .
学校给了我奖学金,所以我不应该恩将仇报,批评学校的招聘政策