你说你会娶我的我说我会娶你的
[nĭ shuō nĭ huì qŭ wŏ de wŏ shuō wŏ huì qŭ nĭ de]
Meaning 'You said you would marry me; I said I would marry you,' it captures mutual commitment or agreement between two people regarding their future relationship, often indicating deep promises made.