" If you don't, you (should) each go your separate ways."

“如果你不这样做， 你们（应该）各走各的路。

You either go your separate ways and never want to see those people again, or you're bonded for life.

你们要么各行各路， 再也不想见到那些人，要么就终身相伴。

Although you have to go your separate ways now, I hope that in a few years' time, you'll come back to visit our school.

虽然大家现在要分道扬镳，但是我希望在几年的时间里，大家也会回到学校来看看。

" To go your separate ways" means to end the relationship, especially a romantic relationship, so each person can do what they want to do – not be married anymore.

” “分道扬镳” 的意思是结束一段感情， 尤其是恋爱关系，这样每个人都可以做自己想做的事——不再结婚。