--We'll always be together. It's a promise.
They were such very kind, dear, beautiful words.
But at the same time, they contained a fragility that inspired an immeasurable fear within - just like the thin wings of a butterfly, turning see-through when their scales were wiped away. Or perhaps even like a crimson rope, connecting those who had exchanged the vow. Once severed, it could not easily be retied. The fact hinted at a particular outcome.
People can't be together forever. They live, and then die, separately.
Despite this, the promise remained alive and well. Even were it not visible to the eye, it surely must be so.