They thought they could defy gravity with their kiss, maybe just for a second, they thought gravity wouldn't let their ascent be their downfall. However, reality had unspoken laws and gravity; a general theory of relativity, that needed to be followed. Unfortunately, they had to make a painful collision back into reality. 

At this moment, they were like magnets in a way, once they were in the same state, they repel. And as magnets do, they grow attracted to their opposites. Sana developed somewhat of an interest on Dahyun, solely on the fact that she knew that the girl was unattainable. 

This time, it didn't hurt as much for Tzuyu as it did when she was younger. A feeling of inadequacy drowned her for the first few fleeting moments, but she learned to adjust, as she always does. She's found a coping mechanism. 

It wasn't as if it was painless for Sana either, she wished she could love who she loved but for now, she just simply couldn't. 

Sana held Tzuyu's heart and Tzuyu, Sana's. Neither wanted to risk holding it too tightly, crushing it and neither wanted to risk holding it too lightly, dropping it. They kept the hearts they held in vaults, only to be uncovered when they absolutely needed to.