A/N: Welcome to my fic! It's multi chapter, Cas/Dean, Human!Cas, no Wincest whatsoever, and various POVs will be used. It's slightly AU, in that it's set somewhere between the time that Cas turned human and the last episode of Season 5. In the show, this might have been about a day; in this universe, it's more like a few months.

I hope you enjoy it; please review and let me know what you think. It really helps me to know that somebody is reading and doesn't think it's complete crap! All those who review will receive their very own Dean Winchester, ABSOLUTELY FREE! Now you two can reenact your very favorite Supernatural episodes in the comfort of your own home. Comes complete with a leather jacket and a give 'em hell attitude! '67 Impala sold separately.

Sam would have figured out the whole thing a lot easier if Dean hadn't been so damn straight.

Dean was straight, completely and utterly straight. That was just a fact. And it wasn't the uber-macho homophobic kind of straight that makes you mutter, "Methinks thou dost protest too much." He was the kind of straight that would slap his brother on the ass and call him honey for the sake of a good joke. He was the kind of straight that slept with more women than Sam could count, and struck out with twice as many, but who would be hurt if he thought a single one of them was faking it. He was the kind of straight that unconsciously checked out every feminine form that crossed his path, unthinking, like it was some kind of pervy reflex. So when Sam never saw it coming, he couldn't be blamed.

If Dean had been even a teensy bit bi-curious, then Sam would have raised an eyebrow when Dean and Cas exchanged long, soulful, unflinching stares. Instead, he chalked it up to the fact that Cas was new at this "humanity" thing, and was unfamiliar with staring etiquette, and to the fact that Dean hated to look away first. He hated backing down from anything, certainly not a challenging gaze.

And the weirdly exclusive relationship they had? Yeah, Sam would've started getting suspicious a long time ago if Dean were just a little gayer. But instead he just figured that neither of them really had any other guy friends (excluding Sam, of course, but that was different because he was a brother to Dean and an apocalypse-starting, recovering demon-blood fiend to Cas). Plus, Cas had been the one to pull Dean from hell, which made him like his guardian angel or something, right? So they had a right to be closer to each other than they were to everyone else (again, except Sam).

But he wasn't completely dense. Even though Dean was completely, totally straight, Sam had started to wonder if Castiel didn't have some kind of crush on him. The dude had rebelled from heaven for Dean, for crying out loud, and he'd had enough time on Earth to learn to stop standing so uncomfortably close. And the way he looked at Dean sometimes, as if his entire world started and ended with him… Sam felt bad for the poor guy. He'd had his experiences with unrequited love back in the day, and it was excruciating. He debated whether or not he should let Dean know what was up. It would be kind of cruel to Castiel, but didn't Dean deserve to know?

And then he saw it.

It wasn't much, really. Nobody else would have even noticed. It was during the latest hunt, after the big bad hell monster got ahold of Dean and started wailing on him pretty fierce. That prompted Cas to take a crowbar to the thing's back, which effectively drew the monster's attention away from Dean but had the unfortunate side affect of focusing its wrath on Castiel. The monster flung the former angel across the room like a rag doll, and his body hit the wall with a sickening smack and crumpled to the ground.

It bought them just a millisecond of time, and Sam managed to aim the Colt and shoot the damn thing. It died instantly, falling to floor with a resounding whumph, and though Sam was grateful, it felt almost… anticlimactic. Dean dragged himself up, bloody and bruised, and scrambled over to Castiel's limp form.

"Cas, talk to me, man," Dean pleaded, rolling him over and clutching him desperately by the shoulders. Sam, still a bit dazed from his own bout with the creature, stumbled over, a quiet panic buzzing in his chest. Cas couldn't die. He just couldn't. And yet, a trickle of blood was dripping down the angel's forehead, startlingly red against his pale skin. Cas had been human for a while, but it was still unnerving to see him bleed.

Dean slid one arm underneath the unconscious angel, cradling him upwards. "C'mon, Cas," he begged. "C'mon."

Sam couldn't help but think, He's out, Dean, down for the count, now let's haul him to the Impala and patch him up but he stayed silent for the moment. He knew Dean just wanted a reassuring glimpse that Cas was still in there, still fighting. Instead, he crouched down beside him and put a hand on his shoulder.

Suddenly, Castiel's eyes rolled open, dilated pupils struggling to focus. "Dean?" he groaned, his hand clutching Dean's sleeve.

Dean let out a shuddering breath, and a shaky smile split across his face. "Shit, Cas," he exclaimed. "You scared the hell outta me. You gotta be more careful."

Even through the fog of pain, Cas looked irritated. He closed his eyes. "My mistake," he ground out, gritting his teeth. "I suppose I was preoccupied with saving your life."

Dean grinned, he genuinely grinned, and shifted his grip on Cas (who, it seemed, was not quite up to sitting up on his own). "You just like playing the hero," he teased.

Cas lolled his head so that he was looking up into Dean's face. His lips curled up just tiniest bit, almost unnoticeably. "I don't play, Dean. I am a hero," he quietly deadpanned.

And that's when it happened.

Dean's grin faded into a smile that was faint and soft, and his eyes seemed to hone in on Castiel's, and his head tilted down the smallest fraction, and – here's the clincher – his lips twitched. Just a tiny little twitch, but Sam spotted it all the same. He nearly choked and died of shock right there.

See, Sam knew that face. That was the face Dean had made dozens – no, hundreds – of times in Sam's presence. It was the face he made when he was about to kiss someone.

And he was making it at Castiel.

The past two and a half years began flashing before Sam's eyes, a Sixth Sense -style revelation unraveling. All the staring contests, the weird physical and emotional closeness, the intense loyalty and the one-sided bantering and the out-of-place, third-wheel sensation Sam felt when caught between the two of them – it all made sense now.

Oh my god, Sam thought. My brother is totally having sex with a fallen angel.

Then Cas's eyes unfocused again, and his hand visibly tightened on Dean's arm. "Dean?" he grunted. "I believe I'm going to be unconscious in a moment." And, like clockwork, he slumped and fell insensible.

And then everything was a blur for the next few hours, the exhausting process of getting Cas to the motel and patching him up and then patching themselves up and then debating whether or not he should go to the emergency room because his body wasn't used to being abused like this – it all kept Sam from thinking too hard about what happened. When he finally kicked off his jeans and fell into bed, his last conscious thoughts were, You know what? There's a rational explanation for what happened. There is a rational explanation and Dean will tell it to me tomorrow because I am too tired to freak out about this.

When he awoke, the previous day's events seemed like a bad dream. Cas was asleep in the other bed, peaceful and serene looking, and Dean was sprawled on the futon, all dangling limbs and pillow drool. Totally normal (except for, you know, the Cas sleeping part). A lip twitch? Ha, Dean probably was just having one of those, "I'm so relieved I could kiss you" moments. Better yet, Sam had probably just imagined the whole thing! He cheerfully left to grab some breakfast for the trio, confident that Castiel would wake up any minute and things would be all copacetic from here on out.

How wrong he was.