口是心非绝对是女生的通病
[kŏu shì xīn fēi jué duì shì nǚ shēng de tōng bìng]
It means 'hypocrisy' or expressing something verbally different from one's actual thoughts, especially attributed here generally towards women. The phrase reflects a cultural belief or stereotype regarding how some people may misinterpret or misunderstand what females truly mean sometimes.