Shapeshifting/Melting?

[Oblimo]

Originally Posted by ReignOfChaos

I remember reading a story about two girls, one was a normal girl just living her life and another had the ability to shapeshift. The shapeshifter became a second skin for the first, allowing her to shapeshift at any time she wanted. It was a really good read but I cannot remember the name of it for the life of me. Anyone know what it was called? I think it was something like Two are One, or I'm senile.

Edit: sorry for the bump, I didn't want to make a new thread since this already existed. :/

Two Become One, by Grotto. It wound up being hosted on my site, for various reasons.