Cas didn't like this feeling. When he'd been an angel human emotions were coming to him, but they were coming slowly; very, very slowly. When he became human, however, the emotions seemed to start bombarding him from within. They were loud persistent things, these emotions, and Cas had a newfound respect for humans that they didn't just curl up in a ball in their rooms and give up, like Cas so very often wanted to do.

Cas took a deep breath and steadied himself for a new day. He sat down and attempted to meditate the way Sam had told him. But the moment he managed to clear his mind of everything, thoughts of Dean managed to creep their way back in. Dean who was the center of those emotions that were the loudest and most overpowering (love and lust as Bobby had described it when Cas had gone to him for help). And then, slowly, thought of Sam crept in too, stealing Dean away. Sam was still the cause of many good emotions for Castiel, but of those overpowering emotions, Sam only caused the darkest one. 'Jealousy,' Bobby's voice echoed from his memories.

Cas sighed and quit his attempt at meditation, his mind swirling with thoughts of Dean so bright and shiny it hurt, and thoughts of Sam so dark they threatened to send him into a rage. Cas took a deep breath and clamed himself before he did something stupid. It wasn't Sam's fault that Dean only saw him, he reminded himself. Hell, it wasn't even Dean's fault. But it was there nonetheless, and it niggled in the back of his mind. Another deep breath (so many these days) and he decided to see if he could help the Winchester brothers at least in the research portion of their latest hunt.

Big mistake. The moment Cas got to their motel room door, he could hear the sinful sounds of what was going on inside. Cas decided he must be masochistic, because instead of doing the sensible thing and leaving for a while, like any sensible human being (even one that was until recently, an angel), he let his curiosity get the better of him. He opened the door.

The sight of the brothers, rutting against each other greeted him. Dean was over Sam, pushing two fingers into his mouth. Sam was the first to notice Castiel standing there, and he turned his head to the side, to better see Cas, letting the fingers fall out of his mouth. His voice was rough, Cas had heard humans use the term 'fucked out' when he spoke. "Cas." Just that one word. When Sam spoke Cas' name, Dean realized they weren't alone and he too turned his head to face Cas. Not pausing in his ministrations to Sam, he said, "Angel." The way he said it made Cas blush, he said it with the same tone and voice that Sam had used earlier to call his name.

Cas couldn't manage to push any words past his throat, so he stayed silent. As he watched, the Winchester brothers marked each other, sucking dark bruises into each other's skin. They were announcing to the world that they were taken, possessed by the other. They didn't stop, even as Cas stood there, and Cas couldn't bring himself to leave. They did not acknowledge Cas after that.

Perhaps it was just Castiel's jealousy, but Sam seemed overzealous in marking up Dean, and he could not help but wonder if Sam was always like that or if he was trying to prove something to Cas, about who Dean had chosen. Still Cas could not bring himself to leave.

The angel decided that if he was staying and torturing himself with this, he might as well make himself comfortable, so he sat himself in a chair in the corner and continued to watch the brothers in their sin. As he watched Dean began kissing his way down Sam's body until he reached the juncture of his legs. Then, looking up at Sam with a strange intensity in his eyes, he sucked Sam into his mouth. Sam threw his head back and arched his body off of the bed in an obvious attempt to shove himself deeper into Dean's mouth. After about a minute or so of that, Dean removed his mouth and began to tongue his way down until he was at Sam's entrance.

Castiel watched in fascination as Dean's tongue encircled the tight ring of muscles a few times before gently pushing in. This action did not cause Sam to arch; instead it made him wriggle and press down, as if encouraging Dean's tongue to go faster, deeper inside him. Even from his vantage point, when Dean pulled back Castiel could see that Sam's hole was shiny with spit and slicked open. After a moment of admiring his handiwork, Dean pulled up and drew Sam into a kiss. As their tongues battled, Dean began to slowly enter Sam.

This time Sam made no movement at all. He stilled completely as if he was trying to absorb every sensation as Dean filled him up. When Dean was all the way in they rested for a moment together before the movement began. And then they were pushing into each other and pulling away from each other. The movement started off slow and smooth, but the longer it went on the faster and more erratic it got. Finally Dean stilled and let Sam's name fall gracelessly from his beautiful lips, seconds after which Sam also stilled, though he made no sound, and Castiel could see the results of his orgasm spread across his and Dean's stomachs.

The sight before his eyes, two brothers so wrapped up in each other that they had either forgotten or didn't care that he was there, finally gave him the strength to walk away. What was that old human saying? "If you love something, set it free, if it was meant to be, it will come back," or something of that nature. Cas knew now that it was not meant to be because to set something free, you have to have it in the first place, but Dean had always belonged to Sam first and foremost. Many of the humans also believed there was someone out there for everyone, so Castiel thought that perhaps he might try to go find the one he was truly meant to be with….