揭疮疤

Traditional (Taiwan): 揭瘡疤

jiēchuāngbā ㄐㄧㄝ ㄔㄨㄤ ㄅㄚ

    • to bring up someone's secrets or shortcomings
    • to reopen an old hurt

Character by character

Saying俗语俗語

Idiom惯用语 · In everyday use

Literally
tear off a scab
Meaning
To bring up someone's secrets or shortcomings, reopening an old hurt. Critical.

Sources