Author's Note: Yes I know the story was completed but based on the reviews I felt you guys deserved more resolution but THIS IS IT I swear lol. Thanks for reading. Hope you enjoyed the story

Cas knew what had happened as soon as he arrived at the bunker. He immediately smelled Omega heat pheromones (obviously Sam's), Dean's distinct Alpha scent and two sets of cum and sweat mixed together. All that could only mean one thing. Dean had mated with Sam.

Cas unnecessarily fixed his trenchcoat as he cast his eyes up the stairs to where he knew the lovers would be lying. He had to keep his hands busy, else they would go to his chest where a strange unpleasant feeling was taking root. Cas knew Sam was an appropriate mate for Dean.

He fiddled with his tie. His breathing had shifted slightly so the tie must have been too tight.

Their being brothers was irrelevant; it was more a social taboo than anything really harmful. After all, the ancient Egyptians had joined brother to sister for years and their civilisation had really been one to behold. The way Sam and Dean pushed each other forward and pulled each other back when necessary…they needed it. The world needed it.

Cas moved over to the long desk and began to tidy it. Sam had obviously been doing some serious research. There were papers all along the desk and even on the floor. Cas leaned over the desk to pull a sheet towards him and ended up gripping the edges of the table like they were driftwood and he was drowning. Sam and Dean were together, they loved each other, all was as it should be.

It didn't matter that Cas would have done anything to be the one in Dean's arms.

It didn't matter that seeing the twinkle in those perfect green eyes when Dean smiled made Cas feel the closest he had to Heaven since its doors had been closed to him and his kind.

It didn't matter that Sam had hurt Dean over and over, with his naivete and his arrogance and his sheer stupidity…

Cas got ahold of his breathing and straightened himself up, letting go of the desk. These thoughts were pointless. As an angel, Cas was neither Alpha, Beta nor Omega and could never give Dean what Sam could; a life mating, a child… He was foolish for ever having held out hope that Dean would ever return his feelings. For even if he had, someone would have come along one day to take Dean away. And Dean would have gone.

Cas teleported himself to the room the boys were in, keeping himself invisible. He knew he had to see it for it to be real, for him to be able to move on and past this thing with Dean. And see it he did.

They were both asleep, still locked together with Dean's knot. Dean's leg was slung over Sam's thighs while his arm rested on Sam's chest. Sam's fingers laced through Dean's, connecting them in a more tender fashion. It was a perfect picture of an Alpha comforting and protecting his Omega, even in their dreams.

Cas had existed for millions of years, since the beginning of the world. He had seen love and war, happiness and anger, betrayal and forgiveness in many forms, in just about every one actually. Nothing humans did surprised him anymore. Until he met Dean Winchester. The man's stubbornness was outmatched only by the brightness of his soul. Castiel forgot how rude of a being he was everytime he saw a glimpse of the supernova burning inside the man.

Cas was just an angel. He followed orders and did what he had to do. Simple, cut and dry, that was all there was. But then he found something, something special. Something he could only feel when he looked into Dean's eyes, a purpose, a sense of import, of belonging to something more than just the Heavenly host. Castiel knew for sure he had found what he didn't even know he was missing for over millennia in this man, that he could be whole and he could be happy. But he was wrong

Cas had seen enough. He took his leave.

A few minutes later, the rain began to fall lightly outside. The boys slept through that but the flashes of lightning pierced the sole window high on the wall, illuminating the room. Waking simultaneously, they said nothing, but manoeuvred what parts of them they could, which were stiff from too long in one position. When they were once more still and wrapped in each other's arms, Dean put his lips to Sam's neck. Kissing him softly, Dean whispered

"Did you realise…?"

"What?" replied Sam groggily.

"There's lightning but no thunder."

Chuckling softly, Sam said, "Yeah, I guess that is interesting."

Kissing from Sam's neck down to his shoulder blades, Dean said, "Mom told me once that when it rains and lightning strikes but you can't hear thunder, it's, get this, a special kind of rain."

Raising an eyebrow, Sam turned his head to look at Dean quizzically.

Dean murmured, "She said it only rains like this when angels cry."