[bèi xìn qì yì]
treachery; act in bad faith; act perfidiously; be guilty of perfidy; break faith with sb.; break one's faith; break one's word and forget one's benefactor; go against one's words and obligations; have no sense of gratitude; perfidious involving a breach of faith; perfidy; play false; show one's bad faith; treacherous
perfidiously tear up agreement and contracts
背信弃义地撕毁协定和合同