morder la mano que se da de comer

Meanings:

• 1.

  SpainLatin Americaneutral
  • Literal: to bite the hand that feeds one; to physically bite someone who is giving food or help.

• 2.

  SpainLatin Americaidiomaticpejorative
  • Figurative: to act ungratefully or betray someone who provides help, support, or sustenance.