biting the hand that feeds one

Verb

bite the hand that feeds one (third-person singular simple present bites the hand that feeds one, present participle biting the hand that feeds one, simple past bit the hand that fed one, past participle bitten the hand that fed one)

1. (idiomatic) To cause harm to a benefactor (especially one that one is dependent on, thus with the idea that this behaviour is self-damaging).
   • Granted that it is not "exquisitely rational" to bite the hand that feeds you, yet that is just what clients and patients do which is one reason they need therapy.1967, Rollo May, Psychology and the Human Dilemma, W. W. Norton & Company, →ISBN, page 18