live a lie idiom
过着骗人的生活;过着双面人的生活
to live in a way that is dishonest because you are pretending to be something that you are not, to yourself or to other people
She doesn't know you're married? You have to stop living a lie and tell her. 她不知道你结了婚吗？你不能再骗人了，必须告诉她实情。