你是太阳我是月亮不能相见
[nĭ shì tài yáng wŏ shì yuè liàng bù néng xiāng jiàn]
In literal sense it's like 'You're the sun and I'm the moon that cannot meet', expressing someone feels like separated by distance or time, but also may symbolically suggest differences in status or other barriers that prevent them being together with someone