不足倾城但倾你一生不够相爱但爱你一世
[bù zú qīng chéng dàn qīng nĭ yī shēng bù gòu xiāng ài dàn ài nĭ yī shì]
A romantic way to express devotion where even if someone isn't universally charming enough to mesmerize an entire city (i.e., stunning beauty), they'll dedicate their whole life and infinite love exclusively to one special person in their heart.