This takes place right after Dean tells Sam that he can't trust him anymore.

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Sam stood still, watching Dean. He wanted to say something. He really did but the guilt was squirming in his gut again and Dean's words had stopped him in his tracks. He'd always held that, Dean's trust and knowing that Dean didn't trust him anymore hurt worse than knowing that he'd been the one to release Lucifer.

For a moment, he wished he could go back to being that guy he'd been before all this had started. He'd thought that getting rid of that guy was a good thing because that guy hadn't been able to save Dean from going to Hell, that guy hadn't been able to do everything it took to make sure it didn't happen.

How could he explain that? He hadn't chosen Ruby over Dean because when it came down to it all he'd ever been fighting for was Dean. It had been that way since Dean had picked him up from college four years ago, since Jess died.

Revenge, yes, he had wanted that at first. He'd wanted to kill the demon that took Jess from him but everything had come in perfect clarity when Dean had gotten electrocuted and that doctor had told him that he would be dead in a few weeks.

It had been simple for him back then. He couldn't loose Dean so he'd done everything he could to make sure that didn't happen. He known what he was capable of in order to save his brother then because even after they found out that it was a reaper and that man had died in Dean's place, most of him had felt nothing but relief at the fact that Dean was still with him.

When their dad had sacrificed himself for Dean, he'd felt guilty, yes, and there had been pain but there was also some part of him, as horrible as it sounded, that was thanking his dad, that was grateful. He could survive without John, he couldn't without Dean.

He didn't care if that made him codependent or whatever. He knew what his breaking point was and he'd already reached it once. He couldn't go there again.

When Ruby had first come to him he'd agreed because he had nothing left to lose. She had been offering a way to kill Lilith and he'd agreed. He'd thought of killing Lilith as his final act. After it was all said and done, he hadn't cared what would have happened to him.

Then, when Dean had returned, there had been this distance between them that neither of them could seem to cross. Still, even with that, he knew he couldn't let Dean die again. Cas had pulled Dean out of Hell but he couldn't trust that the angels would pull something like that again.

The fear of loosing Dean had always been there before his deal, made worse by how many times Dean had nearly died. Their entire lives had always been a series of near misses. When Dean had gotten electrocuted that had not been the first time he had been faced with the possibility of losing his brother.

Before he went to college, however, John had been there. Despite how much he had grown to resent his father in his teen years, he'd still known that John would never let Dean die, not if he could help it.

Then their dad had disappeared and Jess had died and he and Dean were the only ones left. Dean had given up his soul to bring Sam back and he knew that he would have done the same thing.

He used to think he knew. Everything was so much simpler before he died.

Now, Dean didn't trust him and he doubted it would matter why he had chosen to accept Ruby's help. He felt a little bit lost without that trust and he had no idea how to get it back.