rén​xīn​gé​dù​pí

one can never know what another is thinking

人心隔肚皮 rén​xīn​gé​dù​pí
one can never know what another is thinking
(idiom) literally meaning people's hearts are separated by their skin; used to mean that a person's true intentions or character are difficult to discern, so one should remain cautious

Frequency

Written text
0.094 per million

Sources

Frequency data
BCC Corpus (BLCU)