behind his back

• adv. 在背后(以不诚实的方式；在别人不知道时)

behind his back的用法和样例：

例句

1. His servants called him Mr Anderson to his face and Creeping Jesus behind his back.
   他的仆人当面叫他安德鲁先生，背后则称他为伪君子。
2. Say it to his face, not behind his back.
   话要当面说，不要背后说。
3. He will flatter a person to his face, and then rundown behind his back.
   他会当面吹捧一个人，背后又说他坏话。
4. He was held with his arms pinioned together behind his back.
   他被捉住反绑着双臂。