praise him behind his back
Chinese idiom, Pinyin is mi à NY à B è Ihu à, which means praise in person and slander behind. The source is guanlang chapter of Wenzi.
The origin of Idioms
"I can't bear to see that my face and reputation are ruined. I live in groups and speak freely. I don't know the shortness of people. I often have the color that can't be offended, so villains are far away."
Idiom usage
As a predicate, attribute, adverbial; used in dealing with affairs and people
praise him behind his back
very much ruffled , one sputters one 's words - jí yán nù sè