沧海带不走蝴蝶蝴蝶飞不过沧海
[cāng hăi dài bù zŏu hú dié hú dié fēi bù guò cāng hăi]
'The Ocean Can't Take Away the Butterfly, the Butterfly Cannot Fly Over the Ocean'. This represents the theme of two people or entities that can't be together because of overwhelming obstacles or fate standing between them.