Dean never had Sam and after John died he was all alone until this angel came along and it was nice at first but then he started dissapearing more and more and Dean became his chew toy. It's not like Dean could leave, he had no one, he didn't even know what could kill an angel. Nothing could save him, and it's not like he wanted to leave, it's better than being alone, right? But then he stumbled into this other hunter, Sam. Both doing the same case and they became good friends pretty fast, they went their seperate ways until one day Dean came knocking on Sam's door. Dean was drunk out of his mind and told sam everything about what was happening to him and Sam always came but he always came too late until one day Sam stayed. And he finally saw the "angel" behind it all.