穿连裆裤

Traditional (Taiwan): 穿連襠褲

chuānliándāngkù ㄔㄨㄢ ㄌㄧㄢˊ ㄉㄤ ㄎㄨˋ

    • to be in cahoots
    • to cover for each other while doing wrong

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
wear trousers joined at the crotch
Meaning
To be in cahoots, covering for each other while doing wrong. Critical.

Sources