behind your back

• adv. 在背后(以不诚实的方式；在别人不知道时)

behind your back的用法和样例：

例句

1. Don't let her catch you breaking the rules; she is likely to go behind your back and complain to the committee about your actions.
   不要让她抓住你违反规定的错误; 她很可能在你背后搞小动作向委员会控告你行为不端。