John was the first to leave him. On November 2, 1983, Dean Winchester lost both his parents. His mother had been lost to the flames, but John had been lost to vengeance and grief. Four-year-olds were not made to be parents, but little Dean realized very quickly that he would have to be just that. His childhood was over, but it didn't have to be for little Sam. He wouldn't let it be. So Dean protected his brother as much as he could, from monsters, from bullies, from his own father. But Dean knew he had failed Sam in so many ways, failed his father, failed everyone. So it shouldn't have surprised Dean when Sam left him too.
Dean couldn't have been more proud when Sam abruptly announced that he was leaving the family business to pursue something that had always been near and dear to Sam's heart: an education. But for Dean, the thing closest to him was his little Sam, and his heart couldn't help but shatter. Four years of his life were spent apart from the boy who had shaped Dean into what he was today. And then Dad left him again when he got a lead on the thing that killed Mom and it was too much to bear.
So he'd dragged Sammy out of college, out of the life he knew his brother deserved because he was too weak to be alone. Sam was never in it 100% though, always looking for an opportunity to return to his apple pie life, but the ugly truth of their lives got in his way. And then Dean did the unthinkable. He left Sam.
He had his reasons, damn good ones, albeit selfish. When that fucker had stabbed his brother in the back he again couldn't face life on his own, his father gone at this point as well. God, and that had been his fault too. Like father like son, Dean spent his time in hell. It changed him into something not even he could recognize. No wonder everyone left him. His father had been strong; not even 100 years in hell could break John Winchester. Dean had broken in 30. God, he disgusted even himself. Not even Sam could handle him then; he picked that demon bitch Ruby over him. It was Dean's fault though, he'd left Sam, but God it fucking hurt him to his core. But at the end of that story, Sam of course was the better person and made the ultimate sacrifice for not only Dean, but the whole goddamn world. Even after God himself abandoned Creation, Sam stood up to the plate. But it left Dean alone again.
He tried his hand at an apple pie life like he promised Sam he would. He wanted it so goddamn bad. He loved Lisa and Ben like he loved all his family: with devoted and almost frightening intensity. He had to leave them, and that broke his heart, but at least their's were kept in tact.
And then Cass, that little shit of an angel that got himself into the highest level of shit possible, Dean loved Cass like his own brother. But he left him too. He chose power over Dean, for reasons that could be considered acceptable, but it hurt all the same.
Fuck and then the worst years of his life. Cass, Sam, and Benny left him. Cass and Benny would rather be in Purgatory than with him. Dean couldn't blame them, they had their reasons. Sam had left him to rot in Purgatory for what? A dog? A girl? Fuck if Dean knew. Dean knew Sam deserved it, more than anyone ever deserved any form of happiness. But fuck if it didn't hurt like a son of a bitch.
By this point, Dean had finally caught on to the trend: he was the reason everyone left, why poor choices were made, why those he loved got killed or worse. It was too much for him after that close call with that goddamn angel Gadriel and his goddamn bullshit. It had cost Kevin his life. Sam had finally had enough too, and they went their separate ways. It was all too much for Dean. He went towards what was familiar. What he spent years in hell doing. What he deserved. He went dark.
It had felt so fucking good to release his anger under the influence of the Mark of Cain. So fucking good, but so fucking terrifying because Dean knew that he had been worthy of bearing it because of the darkness he had kept locked deep inside him, and the Mark had been the key to unlocking it. This was the one time he wanted everyone to leave him. This was the one time they wouldn't leave him the fuck alone. Charlie had died because of him. Jesus Christ, he had almost killed Cass and Sam. The fucking guilt after that, and then the weird-ass connection to the Darkness had happened, God had showed up, and then left them again. Of course.
Dean put on a show of bravado and sarcasm to, how had Azazel phrased it? "Mask all that nasty pain." He hid behind his smart-ass, womanizing mouth. He rarely gave anyone a glimpse at the true Dean: a broken little boy trying so hard to protect a family that didn't want him.
And then Mary.
His whole existence was because of Mary. He and his brother were raised in the hunter lifestyle because of her death. He should have seen this coming, given his track record, given that she hated this lifestyle and never wanted it for her boys. But this was his mother. He had been young, but he remembered when he was still allowed to be a boy, when all that mattered was a cuddle from mom and bedtime stories and pie. Her soft voice and features were as comforting as ever. But something was off. Sam had noticed it. He had too, but in the classic Dean Winchester way he chose to ignore it, figuring that his mother dealt with things the same way he and Sam always had: hunting. But that had never really worked for them either. Stupid, so fucking stupid to allow himself to hope that for once in his life he could have something good. She had tried. Tried to love the boys she no longer knew. But she was still in mourning. Dean knew it was for the best, that this was a healthier way to deal than any of his family ever had. Hell, when Mary's own father had his second go-round on Earth, he never really grieved the loss of his daughter and look where that had got him. No, Dean was smarter than he gave himself credit for. He knew his mother needed this time alone, that it would be better for all of them in the long run. But by the time Mary had explained herself, Dean had shut himself down: don't show them how much you hurt, don't let them know it's killing you inside to be abandoned again. He couldn't even look at her without breaking into a million pieces. He would rather be ripped to shreds by Hellhounds again than rejected by his own mother.
Again, the words of Azazel rang in his ears, "You know, you fight, and you fight for this family, but the truth is, they don't need you. Not like you need them."
But then the door had screeched open and out of the corner of his eye he saw Sam shudder. His brother had been through so much heartache and torture and grief too. Sam had never known their mother, not like Dean had. This was hitting him hard too. Dean would have to do what he did best and go into protective big brother mode. It wouldn't be easy, but they would get through this, like they did everything. So he pushed aside his own pain for the sake of his brother, determined to fix him first.
He remembered the words he had spoken to his mother not long before, "The only thing that we had in this world, the only thing, aside from this car, was each other." And Dean would be damned if he didn't keep his word on that.