深知我爱你你却爱着她
[shēn zhī wŏ ài nĭ nĭ què ài zhe tā]
'Deeply knowing I love you, you love her instead.' Reflects the anguish felt by one person deeply aware of their own love towards another who unfortunately returns that feeling towards a third party. Shows a bittersweet awareness in the face of unrequited love.