They were in love since they could remember. That kind of love which isn't prohibited de facto, but still impossible.
They say you need two love ones to move the mountain. Not always true. At least for them, it was a stupid sarcastic irony. Doesn't work if you are a mountain yourself.
In the beginning, they didn't even have names for each other. Then people came and give them names. But not the beautiful ones like everyone enjoy remembering, but just North and South mountains.
Probably they would live their whole lives with these stupid names, till the North mountain asked South, could she call her Green Tear? Because of her adorable small waterfalls.

"Of course!" agreed Green Tear, "Then I would love to call you Dawn, because of the sandstone which covers you. No matter what part of the day if the sun touches you, it looks like the dawn, and always makes my waterfalls tear."