imagine if Dean had been able to walk into that circle and talk Cain down from his madness, one hand on his shoulder and the other fisted in his thick mane of hair while he looked into Cain's eyes that had seen far too many years and told him that they could both get through this
imagine Cain breaking down in Dean's arms with awful, wretching, far too human sobs as he realizes that Dean will be the only who could ever begin to understand his life and what he has done, even if he had made the wrong decisions where Dean didn't. After all, Dean knew from those 40 years in Hell what it is like to succumb to the evil that festers within.
But they can over come it and they do.
They isolate themselves to Cain's farm and learn every in and out of each other, in every sense. Friends, lovers, confidants, and sometimes enemies.
Sam visits as often as he can when he's not in school. He would come more but Dean never wants to chance him staying too long. It took weeks of convincing, but he had accepted that his brother knew what was best for him. It hurts Dean, but he never wants to make the same mistake Cain did.
Cas all but lives with them, only leaving when there's urgent business in heaven. Once they earn each other's trust, Cain teaches Cas how to care for the bees, how to tend their garden and how to pleasure Dean in the most tantalizing way. That trust goes a long way.
It is after all Cas' hand that controls the fate of both men for all of eternity. Only he knows the location of the First Blade that can end their lives and their constantly oppressed desire to kill. The millennium pass far easier with the calm grace of their avenging angel by their side.
