你非我良人怎么知我深情
[nĭ fēi wŏ liáng rén zĕn me zhī wŏ shēn qíng]
This can be translated to: 'How do you know my deep affection when you're not the right one for me?' This phrase implies that unless you are truly loved by the speaker, there is no way you could understand how much they really love you or someone else.