天上好比鸳鸯鸟地下好比连理枝
[tiān shàng hăo bĭ yuān yāng niăo dì xià hăo bĭ lián lĭ zhī]
'Birds like mandarin ducks in heaven and branches like intergrown plants on earth' is an expression referring to perfect couples who match each other in beauty, affection, and companionship. It originates from traditional romantic Chinese imagery.