肚里蛔虫

Traditional (Taiwan): 肚里蛔蟲

dùlihuíchóng ㄉㄨˋ ˙ㄌㄧ ㄏㄨㄟˊ ㄔㄨㄥˊ

    • person who knows exactly what someone else is thinking

Character by character

Saying俗语俗語

Idiom惯用语 · In everyday use

Literally
roundworm in one's belly
Meaning
A person who knows exactly what someone else is thinking. It is humorous, sometimes mildly mocking. Roughly 'someone who can read your mind'.

Sources