有种怪病叫心口不一
[yŏu zhŏng guài bìng jiào xīn kŏu bù yī]
Translates to 'there is a strange sickness called having the mind say no but the mouth saying yes' which refers to a common situation where one's true thoughts or feelings don't match words spoken, implying hypocrisy or inconsistency between inner beliefs and outward behavior.