他说白头到老才是爱她说细水长流才是情
[tā shuō bái tóu dào lăo cái shì ài tā shuō xì shuĭ zhăng liú cái shì qíng]
This phrase reflects traditional Chinese romantic philosophy, where lasting till old age (白头到老) symbolizes true love, and long-lasting steady emotion (细水长流) represents genuine affection.