double-cross
verb [ T ] informal uk/ˌdʌb.əlˈkrɒs/ us/ˌdʌb.əlˈkrɑːs/
欺骗（帮凶），蒙骗（同伙）
to deceive someone by working only for your own advantage in the (usually illegal) activities you have planned together
The diamond thief double-crossed his partners and gave them only worthless fake jewels. 钻石大盗欺骗了同伙，给了他们一钱不值的假珠宝。