她若不愛對她再好也是徒勞
[tā ruò bù ài duì tā zài hăo yĕ shì tú láo]
It means that no matter how well you treat a woman, if she doesn't love you in return, all the kindness and effort will be in vain. It expresses a hopeless but affectionate state of mind towards someone who does not reciprocate your feelings.