容颜老去我伴你白发苍苍我陪你
[róng yán lăo qù wŏ bàn nĭ bái fā cāng cāng wŏ péi nĭ]
This nickname conveys a deeply emotional and romantic sentiment, expressing a lifelong commitment. It promises companionship through aging, staying together from youth to old age where they grow old gracefully and support each other as life changes.