Dear lord almighty. It's like the PWP That Could. It started out at eight hundred words and pure smut, and morphed into four thousand words with very little smut, and a surprising amount of Sam. One day I will write pure smut. One day.

Title inspired by a Bruce Springsteen song of the same name. I know, Springsteen, Dean would be ashamed, but hey- it fit.

This is in honor of episode 4.18, The Monster at the End of This Book, because I was so ridiculously happy that they went there, with the fanfiction and the slash. Not many shows are brave enough to mock the fangirls, however gently.

Dean wakes up to the sense of wrong and rolls gracefully out of bed. Or rather, tries to. In reality, the sheets tangle around his waist and catch him before he's halfway off, and he has to take a double handful of cheap motel linen and haul himself back up. There's a counterweight on the other side of the bed keeping the sheets pinned. He feels movement from this weight echo through the mattress and a murmured protest as his actions pull the other body closer to him.

The angle is too awkward for him to slip his hand under his pillow for his .45, so he twists around in a way that causes his spine to pop- a gentle reminder that he isn't a kid anymore, and he isn't getting any younger, and he treats his body like crap anyway so old age will be especially vindictive. By the time he fishes the gun out, however, he's mostly relaxed. If there was something in here looking to harm him in any way, it certainly had its chance to do so a dozen times over by now.

He kicks off the restrictive sheets, then yanks them back up when he realizes he's naked. After a moment of desperate scrabbling for any memory of last night, he pushes himself up, letting the sheet pool in his lap and resting his gun against his knee.

The room smells of sweat and alcohol. There are clothes scattered everywhere. He can taste last night's binge through the layer of carpet fuzz on his tongue, and his back aches with a shallow pain, and he feels loose-limbed and relaxed. It all adds up to one pretty clear picture, and it's starting to worry him, because the body pressed up against his leg is very distinctly not female.

He can have his little gay freakout later, he decides- if he even has one; his life is so weird these days that something like unexpectedly adjusted sexual preferences doesn't appear to be fazing him. For now, he simply prays to a god that he'll probably never be ready to believe in that he won't see Sam when he looks over.

This was never a concern before, he thinks wryly. Before he met Chuck, it wouldn't have been even a briefly considered possibility. He wholeheartedly blames the prophet for this newest form of mental scarring.

He readies his gun- because if it is Sam, shooting himself is the only possible recourse- and looks over to his right. And it's the damned angel laying there, flat on his stomach, arm wrapped up around his pillow and face tucked into the crook of his elbow.

Jimmy's stomach, and Jimmy's elbow, Dean viciously reminds himself, because Castiel is only a passenger in that body, a benign sort of hijacker, and that makes what happened last night the most fucked up version of a threesome Dean can even imagine. He realizes he's doing an odd sort of sideways scuttle to his left only as he runs out of bed and falls flat on his back. The angel makes a complaining noise again, because Dean still has a death grip on the sheet and Castiel has been yanked halfway across the bed and had left his pillow behind.

Dean lunges to his feet and across the room, checking the table with his hip hard enough to bring tears to his eyes. He finds a pair of jeans- his, obviously- and a grey t-shirt and throws them on, then begins the mad hunt for his shoes, which through previous experience he knows could be literally anywhere.

At least it's not Sam, some horribly perky voice offers up in the back of his mind.

He wonders when his life so completely jumped the rails, that sleeping with a goddamn angel is the safer option.

"Where the hell are you?" Dean explodes as soon as Sam picks up the phone, his emotions a potent cocktail of worry and desperation and a frozen sort of deer-in-the-headlights panic. He paces away from the closed door of their motel room, which is empty save for one naked, sleeping, semi-fallen angel, then doubles back and paces the other way. He cannot, in good conscience, leave Cas alone and vulnerable in a way so alien to his kind. All the same, the poor bastard doesn't need a front row seat to what Dean suspects will be a spectacular meltdown.

Sam sighs in a put-upon sort of way, as if Dean is being unreasonably demanding.

"You called from the bar, told me you'd scored and I needed to get my own room. Remember?"

"No," Dean says, after a moment's mental flailing. "Get your ass down here. I think I- did something kinda stupid."

Sam pauses, doesn't immediately hit Dean with a rejoinder about nothing new there. Then again, 'I did something kinda stupid' has almost been Sam's theme song lately.

"Like what?" the kid asks, when the moment of tension has passed. Dean glances guiltily over his shoulder, at the closed door.

"Like Cas," he says, weakly.

"What?"

"Cas. You know, Castiel, the angel?"

"You…" Sam begins, but apparently can't find the words. Dean can't really blame him.

"I did Cas, okay? Happy now?" he barks, because pissed is easier than embarrassed.

"Never again, without brain bleach," his brother deadpans, and hangs up.

The Impala is parked in the spot left of the one directly in front of the room. Dean roots around in the back seat for a moment, hoping for some miracle discovery of the alcoholic sort. When that fails to pan out, he sprawls across the hood, soaking in the sun's reflected warmth and trying to ignore the shallow scratches he can feel on his shoulder blades.

Sam shows up fifteen minutes after the call. He doesn't have any booze, but he brings an offering of coffee- crappy motel coffee in a dinky paper cup, but it's strong and black and if Dean isn't allowed any booze he'll take straight-up caffeine as compromise. Then the kid goes over and opens the door carefully, taking a half-step into the room. A moment later he backs out and closes the door just as carefully. Dean remembers dragging Cas almost right off the bed, and banging the table into the wall, and slamming the door behind him, and thinks Sam doesn't truly appreciate how very drunk the angel had to be for this to have happened.

They lean against the Impala's fender, Dean sipping at his coffee and Sam staring at the ground and contemplating the mysteries of the universe, or whatever. After a long couple of minutes, he finally looks up.

"I think this is a whole new level of stupid, even for you," Sam says thoughtfully.

"Thanks, Sam," Dean growls. He pitches his empty cup in the general direction of a nearby trashcan.

"Seriously, is this gonna be a thing, you and angels?" Sam presses.

"I don't know, Sammy," Dean says carelessly. "Angels just do it better. Kinda spoiled me, actually. Anna had this one trick, and I thought it was just her but Cas knew it too, and she-"

"Oh God, just stop," Sam whines, and Dean obliges, mostly because he was lying through his teeth.

And he was a virgin, he wants to say. But it's not his to tell, and bad enough Sam thinks Dean's doing his level best to corrupt their angel without knowing the worst of it. To his knowledge, Cas has never mentioned their little field trip to the whorehouse to Sam, and Dean suddenly wants to keep it that way. He feels a deep, burning pit of shame in his stomach, because he's defiling an angel, a creature of light and grace and beauty, and Dean is dragging him down and staining him with a human taint. He might as well take a knife and cut Castiel's wings off himself.

"We're gonna have to talk about this, aren't we," Dean asks with all the enthusiasm of a child visiting the dentist's office. Sam snorts.

"Define 'we'," he says. "Because I will pay you to never mention this again. But you and Cas? Probably." Sam waits a moment, then claps a hand on Dean's shoulder. "Well, I'm sure you'll make it as painful and awkward as possible." Which Dean figures is little brother speak for 'good luck'.

Dean stares at the motel door and says nothing.

Cas is still asleep when Dean comes in. He considers waiting for the angel to wake up, then decides that he needs time to get it straight in his head, and goes to take a shower instead.

The mirror in the bathroom has one long, smooth crack running almost perfectly diagonal through it. Dean frowns at it, traces his fingertips over it. He doesn't remember it being there yesterday.

He keeps his shower short, and dresses in the bathroom in the clothes he'd grabbed off the pile. His shirt desperately needs washing and he'd somehow lost track of the jeans he'd been wearing earlier and swapped them out with the mud-caked pair he'd worn on their last hunt, but being fully clothed when he next faces the angel is very important.

He was right to get dressed in the bathroom, he sees, because Cas is awake, eyes lazily narrow and tracking Dean. He has yet to actually move, and is showing absolutely no emotion, and Dean abruptly realizes he has no idea what he's supposed to say.

"About last night," he says, and instantly cringes at the cliché. Castiel blinks, a process which seems to take about four times as long as normal.

"Do you regret what happened?" the angel asks after a nice long awkward pause, voice sleep-rough and quiet.

"Shit, Cas, don't you?" Dean demands, because he's not the one they should be worried about here.

"No more so than many of my actions lately," Cas says serenely.

Someday, Castiel will slip up and give an honest, straightforward answer to something. Dean imagines there will be truth serum involved.

"Well, it won't happen again," the hunter promises, since he has no idea how to interpret that. "We were both drunk, did something kinda stupid-"

At least we did it with each other, he is going to say. If someone was going to go home with an angel last night, better it was someone who knew what he was and had at least a vague idea of how to handle him.

That was what he was going to say. Castiel's next words neatly derail that plan.

"I wasn't drunk, Dean."

"Sure you were," Dean's mouth says, while his brain disengages to process this new information. "You probably didn't even realize it. You haven't been drunk before, that I know of."

"I didn't drink anything last night," Castiel clarifies patiently. He seems to realize that he has completely shattered Dean's understanding of what was going on here.

"You weren't- I was-" Dean stops, runs a hand over his face and tries to find the best way to phrase this. "I didn't-"

The very idea that Dean might have somehow forced himself on Cas is ridiculous, and even insulting. Not only is it something Dean would never do, but the idea of anyone physically forcing Castiel into doing something he didn't want to is laughable. On the other hand, the angel has recently displayed a fairly alarming tendency to do whatever Dean tells him.

"You didn't- just because I asked you-" he tries again, still trying to say it in a way that doesn't scream rapist.

Fortunately, Cas gets it. "No."

His mouth wants to go for the next obvious question- then why?- but his brain is gibbering safer subject! safer subject!. He tells his mouth to mention the weather, in a very and we shall never speak of this again sort of way, but it once again goes off and does its own thing, albeit in a mostly neutral area.

"Why were you asleep then? I thought you were passed out," he says, which at least is a somewhat comfortable subject.

Cas closes his eyes as if considering. He pushes himself up after a moment, rolls over and levers himself up until he's reclining on his elbows, sheet slipping halfway down his chest. Dean looks at him and somehow feels overdressed.

"I was… recovering," the angel says finally, in a tone Dean hasn't heard from him before. It almost sounds like self-consciousness, if Cas were capable of such a thing.

"You were…" Dean begins, then bites off his words as he remembers the mirror. He looks up, instinctively, then moves over and turns on the room lights. He hadn't tried before- it's an east facing room and the sunlight filtering through the gauze-curtained windows had been all the light he needed.

There are three lights in the room. One doesn't work at all, one pops and snaps and stutters into darkness, and one gives a sullen glow at about half the intensity it had possessed before last night.

Dean considers this for a moment. He half-turns to face the angel, and oh god, his mouth is doing that no-brain-involved thing again.

"Is this a common problem, or was I that good?"

Cas gives him a look, one normally reserved for children who are sitting on the lawn eating the grass, and Dean figures it's totally appropriate that the first real emotion the angel fully masters is disdain.

"I'm kinda surprised you didn't blow out my cell phone," the hunter continues, and the look is dialed back a few notches, back into almost embarrassed.

"I did attempt to- restrain myself," the angel says stiffly, and Dean's brain finally kicks into full gear and he manages to swallow the well that couldn't have been much fun that wants to come out. He certainly doesn't immediately think about having sex in a field so Cas can really let loose and just enjoy it, because sex in the grass is not nearly as much fun as people think, and he isn't having sex with the angel again besides.

When he looks back over at Cas, he finds the angel has sat up properly, legs tucked in close, sheet slipping dangerously off one hip. Cas is giving him that wide-eyed, slightly hurt look, and if he were anyone else Dean would swear he's being played right now.

"You did not enjoy yourself last night," he says.

"No," Dean says instantly. "Yes. I don't know, maybe?" He hates those sorts of questions, the ones where any answer he gives sounds wrong. "No, don't- look, this isn't about me, okay?"

Cas tilts his head a little and waits.

"I'm pretty sure angels aren't supposed to… you know," Dean says, a little weakly, and instantly knows he's stepped wrong. Cas' jaw goes tight and his eyes narrow.

"You are the one who encouraged me to make my own choices," the angel says tightly, accusingly.

"Yeah, okay, fair enough," Dean backpedals. "But just so you know- this one? Bad choice. Very bad."

"Why? Because it's you?" Cas hasn't backed off at all. He pins Dean with that look of his, the one that just screams angel, the one that makes Dean think Cas can see straight through him to his mind and his soul and read him like a book.

Dean looks away, unable to bear that intense gaze. When he looks back, it has softened into something unreadable.

"There is no one else I would rather it be, Dean," Cas says simply, once he's sure he has Dean's attention.

All Dean knows how to do is fight. He's seen too much to play civilian and done too much to ever be truly happy again, and he wants to rail and fight at Castiel's words, because he's Dean fucking Winchester and he has done nothing in his life to ever deserve having an angel in his bed, giving him that affectionate look.

But Castiel is an angel, and angels are patience and wisdom and hope, and Dean knows he will never convince Cas that he isn't worthy of this.

Dean goes over and sits on the other bed, scrubbing a hand across his face as he goes. He rests his elbows on his knees and braces one thumb against the bridge of his nose, eyes focused on something a thousand miles away. He can see Cas shifting around on the other bed but doesn't look at him.

Finally he looks up, finds the angel facing him, watching him with dark eyes.

"Now what?" he asks.

"I will leave, if you want," Cas says. No emotion, no indication of his personal preference. Just an option, laid out on the table. This time, however, Dean hears the answer in what Cas isn't saying.

I could stay, if you like, is the other half of that.

Dean isn't quite sure what he does that tells Cas his choice. Maybe it's as simple as the angel really can read his mind, and watches him arrive at his decision. He untucks his legs and slips out of the bed and Dean instinctively jerks his gaze up over Cas' shoulder, because apparently angels have not an ounce of modesty and even if he did all sorts of unspeakable things to that body last night, this is entirely different and far more intimate than he's ever been comfortable with.

Cas touches him on the shoulder, pulls him gently to his feet. His right hand slides up Dean's left arm, under the sleeve of his shirt, stopping just shy of the scar. When Dean says nothing, Cas lays his hand over the mark it had left. Dean watches the contact, feels a shudder of something like anticipation trace its way up his spine.

The angel tilts his head, catches Dean's eye and holds his gaze. Dean has no idea what he wants, and so says nothing, and Cas takes his lack of protest as permission.

There's a gentle touch along his skin, like a thousand feathers brushing against him. Then the touch turns heavy, and Dean gasps, sharp and short. It's warmth and weight, the right pressure in the right places, a knowing hand that finds all the best spots, nerves singing on the very edge of pleasure-almost-pain. It's better than any sex Dean has ever had.

He comes back to himself abruptly. His face is buried against Cas' neck, his legs jelly- he's upright only because Cas is holding him up, he realizes.

"Damn, Cas," he rasps out, and Cas huffs a short breath. It's the closest to laughter Dean has ever seen him get.

He wraps a hand around the back of Cas' neck, threads his fingers through the short dark hair, and pulls the angel in for a kiss. Here, Cas is still just a student, unsure of the proper motions, but learning fast as always. They break apart only when Dean remembers that one of them eventually needs to breathe.

"I'm gonna vote stay," Dean says raggedly.

Castiel smiles.

The mirror in the bathroom cracks again, sliding out of its frame and shattering across the bathroom floor. The one remaining light bulb flickers and explodes, shards small as grains of sand, white-hot pinpricks on bare skin. The windows gain a spiderweb of cracks running through several panes. Dean's cell phone gives a weak sort of fizzle and dies.

Dean listens to the destruction around him with a triumphant grin. It's almost as intoxicating as the hoarse screams he coaxes out of the angel beneath him.

"I don't want to know," Sam says, later, when they meet up for dinner. Cas is gone, off doing whatever he does when he's not hanging around with them. He'll be back soon enough.

Dean is busy programming all his contacts into his new phone. He'll have to take better care of it, he thinks- these things aren't cheap, and no way in hell is he gonna find himself explaining to Bobby why his number keeps changing.

"Know about what?" Dean asks, popping another fry into his mouth as he works.

"The walls were shaking, Dean," Sam informs him irritably. "Kinda obvious how your talk with Cas went."

Dean grins around another fry. He takes down a mental note- as much fun as it sounds, no backseat sex. Cas isn't trashing his car.

"Did some damage to the room," he says cheerfully. "Probably better do a fast checkout."

Which means leaving the key on the table and hitting the road without checking out at all, and tossing the card they'd used to pay. They've done it before, mostly when something ambushes them in the motel and they leave big puddles of blood on the floor and large holes in the wall.

"I don't want to know," Sam says again, sounding almost pained.

"You have no idea what you're missing, Sammy," Dean says, because he just can't help himself.

"Seriously, Dean, I will shoot you," his brother snaps, and Dean laughs.

Sam goes online and catches wind of something, possibly a black dog, up in Montana while Dean is inhaling his second piece of pie. They stop by the motel only long enough to grab their stuff and end up making a run for it, a very understandably pissed motel manager storming after them and cussing them out in three languages.

They spend a day on the road and another in Montana, chasing rumors, and they don't talk about it at all. There's really nothing to be said.

Cas shows up the third day. He lets them drag him around town with a long-suffering sort of tolerance, and eats about half a burger at the dive they stop at for dinner, and watches in bemusement as the brothers fight over the after-dinner TV viewing choice.

Then, after Sam goes and gets his own room, Cas accidentally implodes the TV, and they have to skip out on yet another massive repair bill.

There's no end to the grief Sam gives him, but Dean can't help but think that he was actually right, back at the beginning.

Angels just do it better.