Sam lay down to rest on his bed. It had been a long week of studying then hunting, and Dean had finally left him alone. His brother had flitted off to some bar to find some girl; all Sam wanted to do was sleep.

Just as he was dozing off he heard a, not yet so familiar, flutter of wings signalling Castiel's arrival. Castiel had never appeared without Dean around, Sam got the feeling he made the angel uneasy with the demon blood running through his veins; yet Castiel didn't seem disappointed with Dean's absence. He glared at Sam menacingly. It was a little scary, when not compared to all the shit Sam had seem, but still a little scary.

"Uh, hi Cas. Dean's not here, can I help you with something?" Sam asked awkwardly, sitting up in his bed.

Castiel simply nodded his head, staring at Sam's face as if he were about to dissolve it (or fuck it). He looked half-pissed, half-horny which was terribly confusing.

"You wanna elaborate?" Sam groaned, slightly irritated. He was too tired to be putting up with Cas' angel shit, especially without Dean as a buffer.

"I know what you're doing," Castiel said in dark accusation, "and I would like you to stop."

Sam frowned, confused, "You know I'm not drinking demon blood!" Where could the angel had gotten that idea? Sam hadn't had a drop since… Castiel was just being an ass. Trying to get Sam to confess to something he hadn't done.

"Do not patronise me Sam! We both know this has nothing to do with demon blood."

Now Sam was really confused, "Cas I really don't know what-"

"Enough," Castiel interrupted, "stop these incessant fantasies at once. I do not appreciate this at all."

"Uh… what fantasies?"

Castiel's expression faltered for a moment, he studied Sam carefully. "Do not pretend you know nothing of what I speak."

Sam sighed, rubbing his temples trying to ward off his impending headache. "Listen, Cas. I truly don't know what you're on about. Just explain your problem, and why you think I'm causing it. Maybe I can help you, but stop looking at me like I stole your underwear or something, okay?"

"Okay," Castiel nodded. The request was hardly unreasonable, and Sam's obvious confusion forced him to reconsider the man's role in his problem. "When I'm around you, or thinking about you, I feel… strange."

"Okay, you feel strange. Do you mean sick?"

"No, not sick at all. I feel good." Castiel frowned, trying to think of the words, "You are affecting my mental and physical state."

"Just because it happens around me, doesn't mean I'm doing it."

"No it does, because of the fantasies I should not be having!" Castiel said loudly, his voice hinting with panic. "I cannot focus. I even need to wait for my body to recover. It's awful."

"Okay, what fantasies?"

"You are naked, and I am also naked. Then we are naked on the bed, and I feel amazing. And then we-"

"Okay, nope. Just no, Cas. Stop talking."

"Okay," the angel nodded quickly; Sam sounded alarmed and this frightened him, but he honestly hadn't even gotten to the best parts.

"Nothing is happening to you. I mean, normal human things are happening to you. Just, go jack off or something." Sam's cheeks were a deep red and he was hysterically avoiding eye contact.

"I don't understand." Castiel said in a small voice. He waited for Sam's face to return to its natural colour and not wanting to startle him further.

"It's arousal, sexual arousal. You want to have sex." Sam said quickly.

"With you?"

"Fuck. Apparently, yes."

Castiel stood still for a moment in silent shock. It was not Sam but himself that was causing this effect on his body? "Oh, I am making you uncomfortable," he realised out loud, "I apologise Sam."

Before Sam could respond, Castiel was gone again.

It was a full 3 weeks before Sam saw Castiel again. One of the few occasions where Sam and Dean got separate rooms, the stress of each other's presence becoming too much. Sam was lounging around, sulking from a recent fight with Dean when Castiel showed up. He just appeared on the bed completely fucking naked; unless a large bouquet of roses covering his crotch counted as clothing, which in Sam's book, it didn't.

Castiel gave Sam a look that actually managed to tingle his arousal, he vaguely wondered where he had learnt to look at people like that.

"Hello Sam," Castiel drawled.

"What the fuck are you doing?" Sam demanded, with a stern no-nonsense tone.

For a moment Castiel looked slightly perplexed and… nervous? The celestial being that raised his brother from hell was lying naked on his bed looking at him nervously. "I'm seducing you," Castiel stated, as if it was obvious.

Sam cleared his throat uncomfortably, "it's, uh… not working."

Castiel gave him a dejected look, "oh," he mumbled, sounding like all the air just came out of his balloon. "I have other methods," he added hopefully, "I can give you chocolates as well, I only thought both was going a bit overboard. Dean said-"

"Woah," Sam interrupted, "Dean told you to do this!?"

"I asked his advice because he is the most successful person I know when it comes to romantic endeavours. Although I neglected to mention it was his brother I intended on seducing."

Sam sat with his mouth open, unsure of what to do. Ever since the first time Castiel came to him, he had been thinking about it; about kissing Castiel, touching, fucking, he couldn't get it out of his head. But he could not get past his reluctance

"Castiel…"

"You want to," Castiel accused, "I am and angel, don't you think I know these things?"

Sam blushed heavily, shame and guilt prompting his deflated expression. "I do," he confessed, "doesn't mean I can, doesn't mean we can."

"I know the importance of Dean's ignorance to this," Castiel stated, "if that is your concern. I assure you he will never know."

Sam said nothing and Castiel got up, moving the bouquet of flowers to reveal his straining erection. Sam moaned out loud, covering his mouth with a hand in embarrassment. Castiel's body had always been hidden from him under three layers of clothing and to see him naked was truly spectacular. Castiel was very pale under his clothes, Sam could see obvious tan lines on his arms and neck. Sam could see now how much older Castiel's vessel was to him, there was a pouch of fat beginning to form on his abdomen, this toned body was looking less defined in some places, starting to soften and sag.

Sam wanted to kiss, lick and bite every fucking inch of him.

But all he could do was stare as Castiel pressed against him, looking up at him with big, blue, curious eyes. "Can I remove your clothing?" he asked gently, and Sam was unable to suppress the convulsion that ricocheted through his body.

"Yes," he whispered throatily.

In an instant he was standing bare. It was surprising though it should not have been, with his powers it wasn't as if he was going to waste time undressing him. Castiel observed his body closely, hands lightly drifting over his chest and abdomen. He seemed considerably more aroused, licking his lips wantonly.

"Lay down," Castiel prompted quietly. Sam obeyed quickly, spreading himself across the soft bed. Though he wasn't as hard as Castiel was, he was sure as hell getting there. Castiel began to pay attention to him, stroking him softly, teasingly.

Sam squirmed underneath him, jutting his hips up a little. He allowed Castiel's curious hands to wander over his body patiently though, he could only assume it was Castiel's first time and he wanted to give him everything he needed.

"Why is your penis bigger than mine?" Castiel asked in a genuinely innocent and curious way.

Sam tossed his head back, feeling his chin peel off his sweaty chest. "Fuck Cas, my everything is bigger than yours. That's-" he paused abruptly to moan at the feeling of Castiel's finger rubbing across his slit, "that's, uh, just how human anatomy works."

"Interesting," the angel mused, "I want to have it inside of me."

Sam bit back a moan, nodding quickly as gasping, "Sure Cas, if, uh, that's what you want."

"Most definitely, I did quite some research about this," Castiel said as a bottle of lube materialised into his hand. "I was told we would need this."

Castiel joined Sam on the bed, thighs either side of Sam's torso as he prepared himself with his own fingers opening him up. Sam took the opportunity to play with Castiel's rigid cock, gently caressing it prompting small little whines out of Castiel's mouth.

"How will I know when I'm ready?" Castiel asked impatiently.

"When you're stretched enough, I suppose. This is not exactly my area of expertise," Sam confessed, still teasing Castiel's cock.

"I'm ready now," Castiel decided arbitrarily.

Sam bit back his protest, not wanting Castiel to hurt himself but not wanting to have to wait a second longer. "More lube, first," he choked out, gesturing towards his cock. Castiel nodded obediently, squeezing the contents of the bottle onto him before sinking slowly onto his cock.

Castiel moaned from above him, pale legs spread as wide as they could; the angel was delightfully unashamed of his body. Castiel screamed something in a language Sam wasn't sure he knew, bucking down onto Sam's thick cock.

"Oh fuck, Castiel!" Sam cried out, clutching to the angel's thighs, thrusting upwards to meet him with the small amount of leverage he had.

"Yes!" Castiel cried, followed by a string of pleasurable sounds. Castiel continued thrusting with no signs of slowing down, he was starting to sweat with the exertion; had he not been so distracted he would have been fascinated by it.

Too quickly, Sam could feel the familiar tightening, his body flexing in anticipation of what was to come. He desperately tried to delay his orgasm because he very much doubted that Castiel was even nearly finished. Until the angel cried out again, putting a hand over his mouth as he came hard onto Sam's chest. Sam arched of the bed, lifting Castiel slightly, as he came – spilling into Castiel's body carelessly.

Castiel rolled off Sam, wincing slightly when he found that it hurt for Sam to exit him so quickly. Surprisingly, he felt tired and wanted to curl into Sam's warm sweaty body and fall asleep.

"Castiel that was – uh, I mean," Sam muttered, still out of breath, "thank you."

"You're welcome Sam," Castiel smiled. "May I sleep?" he asked shyly, "I feel safe here."

Sam nodded in response, pulling Castiel's naked body against his, "Of course."