Disclaimer: Don't own Supernatural.
To Sam it was as if the world had ceased to exist. There was only Dean, his soft lips and hot breath. The air was heavy, actually it was like there was no air at all. And then, there was the need. It was in Sam's skin, it was in his blood - the need to mark his brother, to show the world that Dean was his and his only - before, now, forever and after that.
The first thing Dean felt was shock. It was brief and it was intense but then came happiness, rushing at him like a wave, flooding him. Sam's lips were chapped and hungry, coaxing Dean into submission. It was a side of his brother that Dean rarely saw, but right now he loved it more than ever. He eagerly parted his lips allowing Sam's tongue to slip into the wet, hot cavern. Dean's hands were gently brushing the soft feathers, sending shivers down Sam's spine.
Suddenly a cold wind forced its way between them and they jumped apart. They were both panting, a trail of saliva on Dean's chin, their eyes wide and wild but still locked together.
Then Dean saw something else in Sam's eyes. Something he hated with passion – fear.
"I-I'm sorry," Sam stuttered. "I don't know what came over me."
I know – Dean wanted to say – I'm your mate. But before he gathered his thoughts together Sam was gone.
Sam was sitting quietly on the roof of the motel, contemplating quietly everything that had happened.
Dean was his heaven – Sam was sure of that. But, God, how could that be? It was wrong, on so many levels. First of all, they were both guys. Well, it didn't really matter, but for God's sake – they were brothers. And there was no way in heaven or hell that they will be accepted as a couple.
No one has to know.The voice in Sam's head was quiet and solemn. His heart ached as he recalled Dean's willingness, his warmth. There's no way he would want me. Oh, but he wants you all right.
"Will you shut up?" Sam screamed, massaging his temples gently.
"Will who shut up?" Sam nearly jumped at hearing Castiel's voice.
"Oh, no one," Sam shrugged. "I was talking to myself."
"Dean told me once that it is the first symptom of insanity."
"Well, I never considered myself sane."
"You are, however, horny as hell," Cass stated calmly, seductively. "I could help you with that."
"Wha… how did you know that?"
"I can feel these things."
"You can feel these things. Of course." Sam repeated simply, then realized something. "What? Since when?"
"And you never told us? Why?"
"It didn't seem that important," He smiled. "Besides you and Dean are horny all the time, so what's the big deal?"
"It's one thing when we're horny and we know we're horny and it's the other when you know we're horny."
"Huh? You lost me after the first 'horny' – it sounds so sexy when you say it."
"Okay, who are you and what have you done with Castiel?"
"I am Castiel – I just figured – since you have yet to find your mate – you can use that time in a more pleasurable way and it's not like…"
"I've already found my mate." Sam said coldly and only when he heard the echo of this words still in the air he realized he meant it with all his heart.