情到深处覆水难收爱到深处难以割舍
[qíng dào shēn chŭ fù shuĭ nán shōu ài dào shēn chŭ nán yĭ gē shè]
It describes a deep and passionate love that cannot be easily put down once you are involved. Water that is spilled on the ground cannot be regained, which is used metaphorically to emphasize a situation that can not be undone - deep feelings in this case.