An Angel And His Hunter

When an angel rebels from Heaven, they're seen as an outcast. They're hunted, even. Castiel was no different. He was alone without his brothers and sisters, and without anyone to tell him exactly what to do. He had what the humans called "Free Will". He didn't regret anything, though. No, he was happy that he had done what he had done, and would never go back and change any of it. His reason being? He did it all for Dean. The hunter had captivated him the moment he had pulled him out of hell. Despite them having what he would call a "profound bond", he wanted more. The angel saw many couples over his time on Earth, and now he was starting to crave the affection they had. He wanted to share his existence with Dean, even if they hunter most likely didn't want to share it with him as well.
Additional notes: The only reason I put it as mature is for some cursing and stuff like that.
This is my first fanfiction, so it's not going to be perfect, but I am going to at least try to make it good and cute.