懂中文 Dong Chinese

沆瀣一氣

hàng​xiè​yī​qì

to act in collusion ; in cahoots with

Definitions

沆瀣一气 (沆瀣一氣) 

hàng​xiè​yī​qì

to act in collusion (idiom); in cahoots with; villains will look after one another

Sources