姑娘眼泪很贵别再为狗卖泪
[gū niáng yăn lèi hĕn guì bié zài wéi gŏu mài lèi]
Literally 'a girl’s tears are precious, don’t cry for dogs'. It means one should treasure oneself and not grieve over unworthy people (often used derogatorily towards men with bad character)