Shouldn't

I shouldn't have this, Cas thought.

Dean was curled into his side, snoring softly against his chest. He had a small contented smile on his face, like everything was right with his world. He was happy. They were happy.

I shouldn't have this.

Even as he ducked his head to inhale the scent of Dean's shampoo and to press a kiss against his hair, Cas couldn't help but feel guilty, like he was taking something that didn't belong to him. Shouldn't belong to him.

What had he ever done to deserve this?

Cas had Fallen. He had lost his faith. He had cursed his absent father. He had turned against his brothers. He had slaughtered hundreds if not thousands, on Earth and in Heaven. He had tried to play God. He had led his followers into disaster. He had wrought chaos. He had destroyed everything.

He had even betrayed Dean. Worse, he had hurt his brother, a sin that should have been unforgivable. He had released the Leviathan, indirectly causing the death of Bobby Singer, the man who had become like a father to Dean. He had abandoned Dean in Purgatory and spurned his attempts to save him. He had allowed Naomi to brainwash him into beating Dean almost to death. He had failed to trust and confide in Dean when it mattered most. He had screwed up, time and again.

Dean should hate him.

Cas couldn't understand how Dean could be here with him in this moment, nestled comfortably in his arms, trusting him, loving him. After everything they had been through, after everything Cas had done, Dean should have kicked him to the curb a long time ago.

It didn't make sense.

The first time Dean kissed him, Cas hadn't reciprocated. He had been frozen in shock, unable to comprehend what was happening.

"Dude, I know you know how to do this. I saw you kiss the hell out of Meg, remember? Get with the program."

Dean had kissed him again and Cas had been forced to consider the possibility that he wasn't dreaming or hallucinating.

"Why?" he had blurted.

Dean had just shrugged. "Life is short, especially for a hunter. I don't want to waste any more time. So can we please stop talking and make out already?"

Unable to resist, Cas had kissed him back.

But he shouldn't have, because this shouldn't be his life. He shouldn't have a home with the Winchesters. He shouldn't be considered a part of their family. He shouldn't be able to cuddle up with Dean on the couch to watch old Western movies and have the hunter fall asleep in his arms. He shouldn't be allowed to have everything he had ever needed or wanted, personified in one perfectly imperfect man. He shouldn't be happy.

It wasn't right. He didn't deserve this. He deserved to be rejected, cast out and alone. He deserved pain and torment and eternal suffering.

He didn't deserve Dean.

But, God help him, he couldn't walk away. He knew it was selfish, but he wanted this. He wanted this with every fibre of his being and it scared him to death, because he knew that if there was any balance to the universe, Dean should be cruelly snatched from him just as they were learning what it meant to be happy.

He feared that loss more than anything. It would destroy him, utterly and completely, and it would be nothing he did not deserve.

But he clutched Dean closer and closed his eyes against the tears. "Father… if you're out there… please let this slide. Please don't take him away from me. For all that I've done wrong, if I have ever done anything right, please… please let it be enough. Please let me have this. I am begging you."

Silence was his only reply. Cas opened his eyes and stared down at his hunter, watching the slow rise and fall of his chest, fervently hoping that Dean wouldn't be killed for his audacity.

Each breath eased the tight knot of fear in his gut.

For now, at least, it seemed the universe was turning a blind eye.

Cas silently vowed to make the most of every moment, because there was no way to know which would be their last.

He bent down and pressed a trembling kiss against Dean's eyelashes.

Sleepily, Dean blinked up at him and a smile spread across his face. "Hey."

"Hello, Dean."

Dean arched up to kiss him, and even though he knew he shouldn't, Cas kissed him back.