Sam leaves when he's twenty, to shouts and curses, and promises to never come back.

Dean watches him leave with tears in his eyes (a fact he'll deny furiously when asked later), knowing that this is something he has to do, but hating it at the same time. He knows Sam just wants to run from this life, but he doesn't understand why he had to run so far, run to California, run all the way to law school of all places.

Well, maybe he does understand why he had to run. But why did he have to leave Dean?

Sam leaves when he's twenty two, slamming the door of the Impala and stomping down the road, his laptop slung over his shoulder.

Dean watches him leave, in the rear view mirror. The car seems bigger now he's gone, and it's stupid to think he won't be back, that this isn't just for a couple of days, but he can't help it. The last time Sam walked away, it was for two years, and old habits die hard sometimes.

His heart still soars when he sees Sam at the Orchard though. Even if he didn't need his help though. Obviously.

Sam leaves when he's twenty six, walking out of the motel room without a backwards glance, leaving Dean broken and close to tears on the floor.

Dean watches him leave, his throat burning with sobs he won't let out, and the strangling attempt from his kid brother. It hurts more this time, than any other time someone's walked out of his life, because this time, he drove him out. John Winchester's words echo in both sons' ears, twisting knives in old wounds.

It's not the first time Sam leaves, but it might be the first time he doesn't come back.

Sam leaves again when he's twenty six, hitching a ride with a grizzled trucker, still not looking back.

Dean watches him leave from a park bench, holding War's ring so tight in his hand that it'll leave grooves in his palm. This time, Sam left because he wanted to. No one told him to leave, no one threatened him, he just left. Left to protect the world from the Winchesters.

If Dean's heart was breaking all over again, the carefully glued together pieces breaking again, he'd think, and agree. Together, they're dangerous. Apart, they're lonely, but the world is safe.

Sam stays when he's twenty eight, blood on his face, some his, some not.

Dean watches him face Lucifer. Watches Lucifer ask him the final question.

But he says no, and he pays for it.

They fight, hunters and angels against hell, and they win, but at what cost?

Dean runs to Sam, as soon as the fighting is over, sees closed lids and pale skin, and thinks his heart has just about stopped. He prays that Sam is still there, that Sam hasn't left him.

not again please sam no

He's still there, Barely.

thank you god thank you