Balthazar had heard the phrase during several of the lifetimes he'd spent on Earth. It was a simple concept. You didn't tattle on a fellow thief, but you most certainly didn't steal from another one. Balthazar understood it, respected it, and followed it.
Dean Winchester did none of the above.
For a man who frequently committed illegal activities, Dean Winchester seemed to have absolutely no abstractions about sticking in his ratty little nose and putting his filthy little hands on things that simply did not belong to him. More to the point, they were things that belonged to Balthazar. Perhaps it was in spite of that aforementioned fact that Dean Winchester had stolen him. They hadn't gotten off on the right foot and neither had made any attempt in their most recent encounters to even try to get along. Balthazar didn't see why he should. Besides the fact that Dean Winchester was a primate, far below and unworthy of Balthazar's attention, let alone friendship, he had stolen the most precious thing from Balthazar. The very worst thing about the entire situation was that Dean Winchester didn't even seem to realize that he'd committed a crime at all.
Yet he continued to steal from Balthazar. The small, shy, lopsided grins he drew out from Castiel belonged to him. There was an entire eternity before Dean Winchester where Balthazar had been the only one to ever see those grins. They were rare beauties that Castiel only granted him on the rarest of occasions and every time he won one, Balthazar felt a mountain of pride swell in his heart because he had managed to do something no one else could. Only he ever got to see this part of Castiel, this childish, playful side that Michael had tried to so thoroughly burn away and bury underneath a stone cold, business first solider of a God who couldn't be bothered to send his kids a holiday card.
Dean Winchester could scratch his ass and win one. And he didn't even realize what he was getting! Castiel's smiles were gifts from God and Dean Winchester threw them aside with a disregard not even Lucifer could top. It breaks Balthazar's heart to see Castiel in such a state: hopelessly, undeniably in love with something that could never return the love in full. Dean Winchester didn't appreciate Castiel, used him instead as a doormat. Balthazar saw it, Rachael saw it, Raphael saw it—all the angel saw it except for Castiel, too hopelessly enamored with that disgusting pig to see what was right in front of him! Dean Winchester did not give a flying fuck if Castiel lived or died, if he won or lost the war; so long as Castiel was useful to his own problems, he would keep him around. But Balthazar knew—he knew—that the moment Castiel could no longer help them, Dean Winchester would throw him away and never think of him again.
Balthazar didn't want to be there when his brother's heart shattered. His own was still in pieces, barely held together with love and worry, from just over a year ago when Castiel had gone missing and he'd asked around everywhere, asked every one and no one would answer him, but then Raphael came to him—an archangel came to him—smiling something that had made Balthazar's Grace curl deep inside his chest and he said: Castiel is dead. Stop asking for him.
Balthazar's entire world had crumpled in an instant because no, how could it be true? Castiel couldn't be dead, he had survived the terrors of Hell, he had done everything anyone had ever asked of him, he was the youngest captain Heaven had ever seen, how could he just be dead?
Balthazar had died that day too, cut himself off from Heaven and the Apocalypse, wanted nothing to do with it or the rest of his goddamned family, because as far as he was concerned, he had no family anymore. There could be no Paradise for him without Castiel.
By the time news reached him of Castiel's second resurrection, it was too late. He'd been dead too long and he had left Castiel alone, gave Dean Winchester amble opportunity to swoop in and steal away his beloved baby brother.
Dean Winchester didn't even know how much Castiel had sacrificed for him, and yet all he ever did was ask and ask and ask for more. Nothing Castiel gave was ever enough, Dean Winchester always required more and Castiel more than happily obliged, desperate to make this pathetic piece of excrement happy, to feel his love returned. Never mind that Castiel had already given everything he could. He had Fallen because of, and for, Dean Winchester. Fallen.
From favor.
From Heaven.
And, worst of all, he had Fallen in love.
With Dean fucking Winchester.
And did Dean Winchester comprehend what exactly Fallen meant? Did he realize just how much Castiel had given up for him? No, of course he didn't. His head was shoved so far up his own ass it was a wonder he was able to hear anything past his own conceited bullshit.
Balthazar didn't like to think about it.
He rubbed at Castiel's back, his brother's shoulders tense with fatigue and pain even in his unconsciousness, slipping his own Grace in with Castiel's. Dean Winchester made his brother stupid. Castiel never would have attempted time travel, injured as he was, before Dean Winchester. And Dean Winchester didn't even seem to care that Castiel was injured—it had been Samuel who called him and asked for his help.
He gave Castiel what energy he could spare and healed the laceration that swelled at his side. When Balthazar had first seen the copious amount of blood that had stained Castiel's coat and skin, Balthazar had been too angry to speak. He had shut out the grating voices of Sam and Dean Winchester and focused all his attention onto his ailing brother; fortunately, the Winchester brothers had enough sense to just shut up and leave him alone while he did his work.
Castiel's Grace mixed with his own so cleanly, as though God himself had intended for them to meld them together and connect in ways beyond what the others angels were capable of.
Dean Winchester leaned against Bobby Singer's desk, stern eyes glaring down at Balthazar. Balthazar couldn't force himself to grace Dean Winchester with reciprocation. Castiel was his entire world, time and space and Father didn't exist without Castiel and Castiel was hurt and needed Balthazar.
Balthazar longed for the days before Dean Winchester. But they were gone.
Castiel stirred and opened his eyes. Balthazar was elated with the fact that he was the first thing Castiel focused on, with his stern, penetrating gaze.
"Cassie," Balthazar said and then he discovered that he didn't need to say anything. Somehow, that one word was enough to encompass everything he felt, enough to settle all the spinning emotions that raced in his head.
"Balthazar," Castiel said, the name slipping past his lips like honey.
And then Castiel's eyes left him and focused on Dean Winchester.
"Dean," he said, and Balthazar tried not to feel hurt at how different Castiel sounded saying Dean Winchester's name.
"Hey," Dean Winchester said, shifting only slightly from his stiff position. "Nice of you to join us, Sleeping Beauty. Here I thought we'd have to send Bobby to give you your true love's kiss."
And just like that, Dean Winchester won another smile.
Balthazar's glare was hidden by the intense eye contact between Dean Winchester and Castiel.
No, Balthazar thought, the saying was wrong. There was certainly no honor among thieves.