拉紧右手不放开紧握左手一辈子
[lā jĭn yòu shŏu bù fàng kāi jĭn wò zuŏ shŏu yī bèi zi]
Expressed metaphorically, 'Hold right hand tightly without letting go; holding left hand firmly for a lifetime' signifies a promise of loyalty and lifelong commitment in a relationship.