It takes Sam approximately 0.01 seconds the next morning to tell something's wrong.

He doesn't say anything at first, when the three of them meet up as usual to go get breakfast together, but Dean catches the way his eyes flick between them. They're not actually ignoring each other, which would be a hell of a lot easier; everything between them is just really…stiff, and not in the sexy way. Cas has progressed past last night's woeful confusion to wounded pride and Dean's successfully turned his lingering morification into gently simmering resentment. Really, it's just great to see how fantastic the pair is at handling their emotions—Dean feels like Sam must be on the verge of a breakdown after putting up with an entire meal of their failure at communicating their problems to each other.

It's fucking stupid, and Dean knows it. Cas probably doesn't know it, since as far as Dean's aware (not that he's asked, because obviously that would be too easy) he's still at a loss as to what the issue is here. Hell, Dean hardly knows what the issue is himself—so what, Cas laughed at him, Dean practically busted a lung after Cas's epic failure at scoring with Chastity that one time, it's not such a big fucking deal. They're friends, and friends laugh at each other. That's just how it works. Besides, Cas didn't even mean it; he just seemed surprised, and not even unpleasantly so. Still more than willing to go on with what they were already in the middle of.

Sam, thankfully, waits to mention it until just before lunch when they stop at a gas station, tagging not-so-casually along when Dean goes inside to pay. "What's up with you two?" he asks as soon as they're out of hearing range of the Impala. "Is something wrong?"

"Mind your own, Sammy," Dean says half-heartedly. Talking about it is the last thing he wants to do, but somehow he doesn't really have the energy to put up much of a fight.

Sam ignores him anyways and goes on, "Is it the whole friends-with-benefits thing? Is that not working out? Because, you know, it actually never works out."

"What? No, it's—"

"And I think the fact that you and Cas have such a strong friendship—"

"Sam—"

"—combined with your obvious mutual attraction—"

"Would you just—"

"—is a pretty clear indication that you both have deeper feelings for each other than either of you have admitted, and I get that you don't like talking about your feelings, but—"

"Please stop talking—"

"—in this case you're really hurting Cas and you're hurting yourself as well, so I think you really just need to talk about this with him before—"

"Oh my God, will you please shut up?" Dean snaps, loud enough that the gas station's few other customers turn to stare at them curiously. He closes his eyes, praying for patience, and manages to lower his voice to a more acceptable level. "It's not that. At all. Just trust me on this, okay? And as much as I appreciate your concern, it's really none of your goddamned business so please, just drop it."

Sam looks mildly offended, but unfortunately is not sufficiently deterred to let go of the subject altogether. "Well, I think you're wrong," he says stubbornly, "but whatever your problem is, you guys still need to talk about it."

"Oh, for Christ's sake," says Dean, and he leaves an indignant Sam to pay on his own.

Though of course Sam is right. Cas seems to think so, anyways, because when Sam's fallen asleep in the back and Cas has moved up to shotgun (they're attempting to pull another all-nighter on the road—there is a distinct possibility that Lucifer's plans for the Apocalypse involve the Winchesters single-handedly melting the ice caps by making them drive back and forth across the country over and over again) Cas says testily, "I still don't understand why you're upset with me, Dean."

Dean grits his teeth until he can feel his jaw creaking unpleasantly. Can't they just leave it? Because it's not even that he doesn't want to talk about it, although that's definitely true as well; it's that he can't talk about it. He doesn't know what to say. Everyone gets embarrassed some times, right? So what the hell makes this so different?

"If you didn't want me to see your underwear you should have indicated so when I started removing your pants."

Yeah, well, that's the whole fucking problem, isn't it? He did want Cas to see it. He wanted Cas to be as turned on by it as he was. The problem with a lot of sex stuff is, though, that if you take away the sex it's actually pretty silly. "It's not—look, can we just—" His gaze stays focused determinedly on the road as he takes a deep breath, trying to keep a lid on his temper. "Maybe we should just… take a break."

Cas scowls, clearly not impressed in the slightest with the suggestion. "I don't want to take a break, and judging by your initial eagerness last night neither do you."

"I'm allowed to change my mind, okay?" And he has, somehow he has changed his mind—or maybe had it changed for him—but at any rate Cas is the absolute last person he wants to be in bed with right now.

"Yes, but—"

"Cas, there's not going to be a shortage of people willing to fuck you. Just because we're not doing it together doesn't mean you can't with other guys, or girls, or whatever you're into." Though it feels weird to him, saying that, picturing that; he wouldn't say he's feeling jealous, because even though neither of them has slept with anyone else recently they were never technically exclusive, but the idea of Cas actually going out on his own and getting it on with a stranger just seems… not really like Cas. When it comes to humans Cas doesn't appear to feel the need to go out and make friends on his own.

"But I don't want to do it with other people," says Cas, which doesn't really do anything to dispel Dean's ideas about his extreme introversion. "I like doing it with you."

"Try it with Sam, then," Dean retorts, fervently wishing the whole damn conversation to be over. "He's just like me, only bigger. Opa!"

Cas says flatly, "No, he's not. Sam's not like you at all."

And for some reason Dean doesn't really know what to say to this, so he just adjusts his grip on the steering wheel and they drive on in silence. Save for the radio, of course, because Dean can't stand a silent car regardless of who's arguing with whom inside; though unfortunately it's reached the point in the evening where all the stations are either playing retro eighties pop trash or mellow jazz. Not really his style, but he doesn't want to wake Sam by blasting one of his old cassette tapes—and at least the jazz is low-key enough to be moderately inoffensive. No way in hell is he going to risk Madonna making this whole scene even worse than it already is.

After about an hour, by which point the atmosphere between them has finally faded into the background a little and Dean is absently wondering for the five billionth time how the dude who drives the snowplough in winter gets to work every day (because this is the type of thing he thinks about when his mind wanders), Cas speaks up again. "I'll fix it," he says suddenly. "I'll make it up to you."

Dean looks over at him, at his determined expression like he's found the perfect solution and everything's going to work out now, and finds he doesn't have the heart to tell his friend that life isn't usually that easy.

They're still sharing a room—Sam pointedly asks for two at the motel where they end up, clearly wanting them to talk it out—and it's not even that bad, on the surface. They just watch TV like they used to on the nights when both were too tired for anything else, and after about twenty minutes Dean finds his eyelids drooping so he crawls into bed. Cas is still awake when he dozes off, staring intently at the flickering screen as if Friends reruns hold the answers to all life's mysteries. Normal. But the whole time they're together, that night and the next and the next, Dean can feel Cas's eyes on him, like if he stares hard enough maybe he can figure Dean out.

Seriously, the guy's getting frigging bags under his eyes—he's losing sleep over this. And it's progressed to something so much more than someone attempting to regain his fuck-buddy privileges, because the point of that whole setup is that it's no-strings-attached while what they have somehow gotten themselves into is more tangled than an old lady's knitting basket. So many strings attached, in short, that it's gotten about twenty times more complicated than any actual relationship Dean can imagine; like, Dean's pretty sure Sam and Jess never had this many issues to work out, and they were legitimately a couple. The thing with him and Cas, though, is that it's reached the point where he can't actually tell what's wrong anymore: is it Cas trying to be human? Cas just being Cas? Cas trying to help Dean, because that's what Cas always does? Cas getting confused from too much TV? Sam thinks they're in love. Dean thinks Sam's stupid. And Cas just keeps staring at Dean like he's a fucking Chinese puzzle box.

Christ. It's like being back in high school all over again. Sometimes Dean just wants to break down and fuck the guy, to make him stop fucking trying so hard. But pity fucks never end well, and he figures he's already wreaked enough havoc on their friendship without screwing things up even more. So he sits in the middle of Cas's scrutinizing looks and Sam's meaningful ones and thinks that this goddamned Apocalypse cannot happen soon enough, as far as he's concerned.

And then everything changes. Again.

They're out fighting demons. God, Dean's sick of demons. It's just the same rinse-and-repeat routine over and over again, with the added bonus of having your life in mortal peril each time. Really fun stuff. In this particular case it's a small town where nearly all the officials have been possessed for actually quite a while now (it's kind of alarming, to be honest, how long it took anyone to notice), so they're at the city hall chucking around salt, holy water, Ruby's demon-killing knife, and hurriedly rattled-off exorcisms like there's no tomorrow—which, who knows, there may not be—and one of the bastards throws Cas down the stairs.

"Go!" Sam yells at Dean as they exchange looks of horror, and it's not because Sam thinks Dean showing concern for Cas would be super romantic or anything but because now that Cas is mostly human he's just as susceptible to broken necks and severe head injuries and all that fun non-supernatural stuff as the rest of them. "I'll hold them here!"

Dean doesn't stop to argue, taking the stairs three at a time and hurling a facefull of rock salt at some high-end lawyer bitch on the way until he can kneel beside Cas. "You okay?" he asks urgently.

Cas is already sitting up. He grimaces and rubs his elbow where it must have connected painfully (Dean can't help remembering how Cas experiences everything and mentally alters his description to excruciatingly) with the stone steps, but luckily other than that doesn't seem particularly unwell. "Fine," he says, and as he grasps the arm Dean offers him to help him to his feet the hem of his shirt lifts up slightly to reveal the top of his underwear, sitting low around his hips.

Holy. Shit.

He knows that pair—after all, he only bought four. They didn't get thrown out after he fucked things up with Cas, just shoved way down deep in the bottom of that old stag shop bag where he could theoretically pretend they didn't exist; and he doesn't know whether Cas found them by accident or because he went looking for them, but his usual generic guy-underwear has been replaced with something fringed with blue lace. Or rather, Dean remembers, not just fringed with but actually composed of: all he can see right now is the band, but he remembers with blood-thumping clarity the panties composed entirely of the same type of lace that decorated his first trial pair, except in ice blue instead of black. All he can see right now is the band, but that is so much fucking more than enough.

His breath catches audibly in his throat, and he tears his eyes away to meet Cas's gaze. It's steady, serious, they're in the middle of a fight and he just fell down the stairs, remember—but there's something else, just a tinge of… satisfaction. And more than a hint of arousal, too, something that's mirrored almost exactly in Dean's expression if the sudden surge of lust shooting through his body is anything to go by.

Cas has done it, he's fucking done it. Because what their "understanding" lacked in novelty, compared to bringing home someone new every night, it made up for in the relative comfort of familiarity—you don't go bringing out your random kinks on total strangers. Somehow, he's still not entirely sure how, last time broke that for him; but this, this isn't an apology. Not at all. It's better than an apology. After all, most apologies don't leave Dean wanting to fling his gun aside and start groping the person responsible for said apology right here and now, regardless of any demonic activity that may be occuring in the vicinity.

He's not sure how long they stand like that, looking at each other hungrily—probably only a few seconds but at the rate Dean's brain has started firing off urgent signals it feels like a whole lot longer. Then a chunk of marble flies past Dean's ear, missing out on braining him by only about an inch, and oh yeah, they're supposed to be fighting demons right now, aren't they?

"A little help here, guys!" Sam shouts from up above, where the mayor has him pinned against the stair-rail by the neck. Cas shoots Dean one last charged look, half a promise and half a demand and altogether enough to make Dean's knees feel a little bit weak, and then he's running back up the stairs to hopefully stop the younger Winchester from getting his head ripped off.

It takes them another half hour of frantic, non-stop activity to get everything sorted out. Dean's a professional, he's been doing this for years—long enough that he can block everything else out when he has to, because if you don't learn to concentrate you die, basically—but as soon as the last body crumples to the floor with a gust of black smoke rushing out of the woman's mouth and back to Hell, his mind snaps sharply back to the fact that Cas, who is currently a bloody, dirty, hot mess standing only a few feet away from him, is wearing a thong. Shit. He's telling himself not to think about it, what with all the bodies lying around the place not to mention Sam standing right behind them. He's telling himself not to picture it, the lace stretched tight around Cas's sharp hips and the dark, wiry hairs at the base of his cock visible through the sheer fabric and his balls sitting heavy in the garment's crotch because he knows Cas hates jerking off himself when Dean's usually there to help him out instead.

He's telling himself they need to get back to the motel right fucking now.

"Well… that's done," Sam remarks. He drags the back of his arm across his grimy forehead, apparently totally oblivious to the sudden spike in tension between his two companions (which is amazing, because Dean personally can practically taste the heaviness in the air). "Is anyone else hungry?"

"No," Dean says immediately, while at the same time Cas says, "Yes."

Dean glares at him. Cas raises his eyebrows innocently. Sam continues to be blissfully ignorant.

"Yes," Cas insists. "I think we should get dinner."

"Takeout?" Dean suggests hopefully, though they've eaten takeout or similar for pretty much the past three days.

"How about no," says Sam, making a face. "I want real food."

So, much to Dean's frustration, they go for dinner; though of course the Winchester definition of "real food" tends to be slightly different than that of people who actually have a kitchen at their disposal. Dean picks practically the first thing he sees on the menu in an effort to make the outing as short as possible, then starts to wonder if Sam and Cas are somehow conspiring in a torture campaign against him when Sam takes a good ten minutes to make a decision. Beside Dean Cas is being less than helpful as well, leaning forward to rest his elbows on the table in a position that pulls the back of his jeans down slightly and the bottom of his shirt up. Not that he's staring or anything, but by the time their food comes the two vertebrae and half-inch of lace that can be seen in the gap between his shirt and pants seem to have been seared permanently into Dean's retinas.

"So what's next?" asks Cas as they (well, him and Sam, anyways—Dean's still too distracted to remember what exactly the meal in front of him is supposed to be) tuck into their dinners.

Sam shrugs. Apparently the world is taking its sweet time to end, dragging its heels like a gigantic petulant child. "Bobby mentioned something about a possible Wendigo over in Pennsylvania. It's not really that far from here, so I guess we could check that out."

Even as Cas is nodding assent, his left hand slips casually down from the table to twist around his back. Two fingers slide under the lace, running all the way around the back of the underwear, and maybe it really is just an adjustment for comfort's sake but Dean can feel his whole body heating up. His own fingers clench involuntarily around the fork he doesn't really remember picking up in the first place, and it takes an unreasonable amount of effort to keep himself from squirming in his seat—fuck, he just wants to climb into Cas's lap right here, screw public decency, and grind down against him nice and slow until he's begging for Dean to—

How come they're both staring at him? Shit. Say something. Pretend you were listening.

"What?" says Dean.

"I asked what you thought," Sam repeats, giving him a strange look.

"What I thought about what?"

"About going to Pennsylvania."

"Uh." What the hell? Why are they going to Pennsylvania? If the final dick-off between Michael and Lucifer is going down in Pennsylvania, someone's definitely got to reorganize their priorities. "Yeah, sounds great."

"Are you feeling okay?" Sam asks.

"Yeah. Yeah. Fine." Dean tries not to glower at Cas, the corners of whose mouth he can see quirking upwards in the beginnings of a smug smile. And so it goes on, for the rest of the too-long meal. And the ride back to the motel. And the saying goodnight to Sam, which involves far too much time deciding when they should leave the next morning and where to get breakfast and similarly unimportant things.

Finally, finally, they're alone in their room. Dean hesitates, because as much as he wants he's not entirely sure he's just allowed to touch; and then Cas hits him with that stare, that fucking intense stare of his, and the next thing he knows they're tumbling onto the bed in a tangle of limbs and hastily discarded clothing and Cas's mouth is everywhere, kissing and nipping and licking hot, wet stripes down his bare chest. He ends up on the bottom somehow, pinned beneath Cas's weight; which is so totally okay with him, because it means he can't even move without pressing up against the heat of Cas's skin.

Except suddenly Cas's hands are tightening around his wrists, his knees pressing Dean's legs into the bed so that the hunter is effectively trapped. It should probably freak him out—throughout Dean's entire extensive history of being held down against various surfaces the person (or creature, sometimes) has very rarely had even remotely good intentions—but… well, maybe he wouldn't call himself a sub, but sometimes he likes to be dominated. Gets off on having someone else in control, ordering him around, doing whatever they want to him. He hasn't gotten a chance at submission in a very long time, not the kind he likes anyways, since he's too cautious to give someone he only met a few hours ago that amount of power over him, but if Cas wants to go there that's more than okay with him.

"We need to talk," says Cas.

"Huh?" says Dean, who is having a great amount of difficult thinking straight due to the fact that Cas's lace-clad crotch his currently rubbing against his own. It's just really his night for intelligent conversation.

"We need to talk," Cas repeats. "About this."

Seriously? Cas wants to talk now? When he's hard and basically naked with another hard and basically naked guy underneath him willing to do whatever he wants? "No offense, Cas," he chokes out, biting back a moan with some difficult as a slight movement from Cas drags the fabric over his cock, "but I don't think oh my God, yes, I don't think this is really the best time."

"No, I mean, about this in general. I can't read your mind, Dean. I won't know what you want unless you tell me."

Which is a fair enough point, because even though talking about capital-s Stuff isn't part of the Dean Winchester Way he does not want a repeat of last time, especially if it means a veto (temporary or, heaven forbid, permanent) on sex from either of them. Plus, he has to give Cas major credit for the fact that he's managed to keep himself together enough to get that point across coherently.

"Okay," he gasps. "Okay, well, do you know what I want right now, Cas?" He struggles free of Cas's grasp, snaking his arms around the man's back to hook his thumbs through Cas's underwear and squeeze his pretty-much-bare ass. "I want you to get off me, and bring that bag over here, and then I want you to fuck me."

Cas's breath catches in his throat and he just stares at Dean, a little bit nervous and a lot turned on. "Are you sure? I've never…"

"Do you want that?" Cas hesitates, but only for a moment before nodding. "Then you'll be fine. I'll talk you through it." Dean presses a gentle kiss against the side of Cas's mouth, trying to soothe him. It feels kind of weird, kind of overly intimate for two guys who're just supposed to be fucking for fun—but who the hell gets to decide that, anyways? Who gets to say what's okay and what's not for them? His friend is nervous. Dean doesn't want him to be. End of story. He's been this gentle with dozens of nameless girls and a few namelss guys, as well, and no one's ever tried to convince him he's in love with any of them.

So Cas gets up, and Dean can't help palming his own cock as he watches Cas and his only-covered-by-the-loosest-definition-of-the-word erection walk across the room to dig out the lube. "Is there a ring in there, too?" Dean asks, forcing himself to still his hands—he can do that any time. Just a little longer and then he'll be fuck, no, he can't even think about it without his cock starting to ache almost painfully.

After a moment more of pawing through the bag's contents Cas holds up a green rubber ring—green, because Sam let him pick it out and Cas seems to have a thing for green, though Dean refuses to think about why this might be. Tilting his head to one side slightly in evident confusion, Cas asks, "Like this?"

"Yeah. Bring it here."

Dean tugs Cas down onto his lap as soon as he's close enough, sliding blue lace down to toss away with the rest of their clothes and then slowly, carefully stretching out the ring over Cas's cock until it settles around the base. The noise it elicits is a combination of surprise and pleasure at the restricted sensation, and Cas's cheeks are flushed, his eyes dark and his lips parted ever so slightly and Dean didn't even know it was possible to get this hard, fuck. "It'll keep you going longer," he tells Cas. "Make this last longer." Though at the rate they're going now, Dean's the one who'll need the help here. "Give me a minute—you can watch, but try not to touch yourself," he adds, grabbing the lube and slicking up his fingers.

It's been ages since he bottomed for anyone, but the first finger slips in with ease and minimal discomfort; he'll admit he does this to himself once in a while, when he's alone and knows he won't be interrupted for a while. A second finger joins the first, stretching himself out; a shudder rolls through his body as he brushes against his prostate and fuck, fuck he wants to do that again—but he can't, he has to wait, focus on Cas—Cas, who's sitting there watching him with eyes that are just blue-ringed black now. Like watching Dean fuck himself on his own fingers is the hottest thing he's ever seen, like he could get off on this alone—and Dean can see how fucking tortuous it is for him, the way he's fidgeting desperately but keeping his hands knotted determinedly in the bedspread as per Dean's instructions.

Third finger—almost there, thank fucking God, he's not sure either he or Cas can take this much longer—and he can't help crooking his fingers just a little so that they graze that spot inside him again and shit, okay, enough, he needs Cas inside him right fucking now. He pulls his hand out, groaning at the sudden emptiness—Cas, just wait for Cas and oh, wow, the head of Cas's cock is nearly purple with blood despite the restrictions of the ring around its base as Dean coats it in lube with a few clumsy strokes.

And then he's sinking down onto Cas's lap, feeling his cock slide slowly deeper and deeper inside and there's that overwhelming feeling of fullness you just can't get the same way with your own hand. Cas's fingers dig into the muscles of his arms, hard enough it'll probably bruise, and through the haze of his own pleasure Dean can hear Cas gasping, "Dean, oh, Dean, Dean," as he tries to adjust to the sudden hot tightness surrounding his cock.

Dean starts to move, at first just grinding down against Cas because it's been so long since he was filled up like this and right now he doesn't want to lose even an inch of this incredible, burning pleasure; the harder he grinds the more the ring rubs against him too, fuck, and Cas's moans are getting louder—this would be the one night Sam managed to get them a pair of adjacent rooms, goddamnit. Cas pulls him in tighter to press their heaving chests together, and Dean seizes the opportunity to claim his mouth in a messy kiss. It muffles the sounds slightly, directing them instead to vibrate down Dean's throat, but it's also—well, you know what, Dean also just likes kissing Cas, so why the hell shouldn't he?

Okay, enough, enough, he needs more, he needs to feel Cas fucking slam into him—"Move," he moans, "oh, God, Cas, move, please—"

"Only if you refrain from using our Father's name again," Cas says, sounding simultaneously wrecked and disapproving.

"Sorry—"

There's a moment of hesitation as Cas tries to figure out how to do what Dean wants when they're already pressed so close together, and then in a movement that's not particularly graceful but hell, Dean passed the point of caring about that a long time ago Cas lowers him onto the bed, hooking Dean's legs around his waist and grasping his hips; he pulls out, just a little, then pushes gently back in. Except it's too little, too gentle, Dean knows Cas doesn't want to hurt him but right now he just wants it hard, wants to feel like Cas is splitting him open inside. "More, c'mon Cas—I can take it—"

It takes a few tries and a lot of cajoling from Dean to persuade Cas he can take it harder, faster, but finally Cas is pulling nearly all the way out before slamming back in, setting a brutal pace as his brain shuts down altogether and he just seems to give in to what his body demands. Dean's going to feel this tomorrow but right now, right now with spots bursting in front of his eyes every time Cas's cock rams into his prostate, right now with the fucking obscene sound of his own cock slapping against Cas's abdomen with every forward shove—right now it is so fucking worth it.

"Dean," Cas gasps, "Dean, I can't—I need to—"

It's that green ring, dragging this out far longer than Cas would have been able to manage on his own. "Just keep going," Dean urges, because he's so close, so damn close, and with his cock left untouched it's been building up longer, more powerful than usual. "Almost there, I promise—shit, shit, Cas, do that again, Cas—"

He can feel his balls tightening, and the heat that's been growing gradually in him spikes unbearably—Cas draws out as far as he can, and then he's thrusting roughly back in and that's it, that's fucking it, it's shoving Dean forcefully over the edge, fists slamming into the bed with a dull thud as he comes. His orgasm punches through his body in ruthless waves and Cas hasn't stopped, he just keeps fucking into Dean, fucking him all the way through it and this is too much, his eyes are rolling back into his head and Cas chokes out a moan as Dean's walls clench around his already over-stimulated cock—Dean's vision is just starting to clear when he feels Cas's nails dig sharply into the skin at his hips as he wildly bucks forward once more and then he's filling Dean up, head thrown back and muscles shaking and holy fucking shit. He feels like he's just run a marathon, exhausted but tingling with an inactive, satisfied energy. Wow. He hasn't felt this good in ages.

"Fuck, Cas," he says as his friend collapses dazedly on the bed beside him. "That was awesome."

Cas presses his nose against the side of Dean's face and agrees vehemently, "Yes."

"You should wear a thong more often," he adds, pulling Cas in for one last lazy kiss.

"Perhaps. Although I think the look is more suited to you, personally."

Dean's brain is too pleasure-sated to try to read into this, twist it into something it's not that would just get him angry again. Maybe Cas is saying it because Dean's stockier than he is so there's more contrast, or maybe because wearing panties turns Dean on and Cas likes to see him turned on. Whatever. For once he's not going to over-analyze, just bask in the after-glow of their recent activities. The rest of the world can wait one goddamned night.