你可以骗钱骗金但不能骗心
[nĭ kĕ yĭ piàn qián piàn jīn dàn bù néng piàn xīn]
It translates to 'you can cheat for money or treasures but never deceive the heart.' It means material gains can be dishonestly obtained, but emotional betrayals or lies are not forgivable, stressing honesty and sincerity.