海枯石烂抵不过好聚好散
[hăi kū shí làn dĭ bù guò hăo jù hăo sàn]
This phrase means that even eternal vows (literally 'until the sea dries up and the stones decay') are less important than amicable parting ways when things come to an end. It suggests that it's better to end relationships peacefully rather than bitterly.