现原形

Traditional (Taiwan): 現原形

xiànyuánxíng ㄒㄧㄢˋ ㄩㄢˊ ㄒㄧㄥˊ

    • to show one's true colours

Character by character

Saying俗语俗語

Idiom惯用语 · In everyday use

Literally
reveal one's original form
Meaning
To show one's true colours, usually something unpleasant.

Sources