Cheating on the outside
It's a Chinese idiom. Pinyin is bi ǎ ol ǐ w é Iji ā n, which means to use collusion, fraud and other improper means to do bad things. It comes from Wang Hu Gu's Fengshi.
Idiom explanation
Inside and outside: inside and outside; treachery: hypocrisy and cunning. It refers to doing bad things by collusion, fraud and other improper means.
The origin of Idioms
Shen Defu's Wanli Ye Huo Bian Wang Hu Gu Feng Shi (Volume 12) in the Ming Dynasty: "at the beginning of Hongzhi, Wang Hu Gu was a temple to offer sacrifices to the doctor, and Li Guang, a eunuch, was married to Shouning marquis. His exterior and interior were treacherous, so he asked to behead Guang to Xie Zong temple."
Idiom usage
Chapter 28 of Huang Xiaopei's twenty years of prosperous dream in Qing Dynasty: "the man surnamed Zhou is in the library. He doesn't know how much money he has lost. He is a traitor on the outside and wants to embezzle money with this fake book."
Cheating on the outside
individual thinking is as varied as individual looks - rén xīn rú miàn
play off one power against another - yǐ yí zhì yí
the highest are the wise and the lowest are the stupid - shàng zhì xià yú