老娘非你不嫁老子非你不娶
[lăo niáng fēi nĭ bù jià lăo zi fēi nĭ bù qŭ]
Slang for 'This old woman won't marry unless it's you(This old man won’t marry any other). ' The user here tries to appear very loyal to the partner indicating a monogamous desire. Despite adopting informal language with somewhat exaggerated undertones, this actually underscores sincerity towards commitment deeply.