double standard ------- 双重标准

英文释义
A situation in which moral standards and behavioral expectations for one group are quite different from that of another similar group.

例句
My beautiful cousin argues with her conservative parents, accusing them of having a double standard because her younger brother is permitted to stay out late at night with his friends, however she cannot.
我的漂亮的堂妹与她保守的父母产生了争执，指责他们实行双重标准，允许她的弟弟跟朋友在外面玩到深夜，而她却不行。