He's sitting there with the cockiest little smirk on his face, like he knows that detention's a joke and the office hasn't been able to get in touch with his dad to tell him about Dean's most recent violation of the school's rules. No, he's sitting there and grinning, and it's getting on her last nerve.

She'd offered to stay late today – the last day before winter break – just because it's Dean, and Casey's trying not to think about why that is. He's seventeen, which is really only a few years younger than her, and he's hot and it's not like she hasn't heard most of the girls in school talking. "Best night of my life Winchester," and "Oh my god, the things he can do with his tongue," so yeah, she's curious. And maybe sometimes Casey could swear he's flirting with her, and sometimes he winks at her like he knows it's working, but it's not like she would ever – no, she loves her job way too much to lose it over some seventeen year old who thinks he's so cool, who has no respect for authority, and no idea when to stop.

He's a pain in the ass, is what he is, and she's going to put him in his place even if that means staying late and delaying the start to her winter break just to make him sit in detention for that much longer.

It's not like Casey's really in a hurry to leave either – the snow is starting to really come down hard outside, and that'll be a real pain in the ass to drive in. Maybe if she stays for a bit longer the plows will have had a chance to come through and clear things up a bit.

There's a soft knock on the door and Clark is peeking his head in, surveying the room quickly before turning back to her. "My I see you for a moment Ms. Bates?"

"Certainly." She shoots a quick look at Dean, who grins at her and raises his eyebrows like she's going to do something naughty with the principal. Ugh, as if.

"The weather forecast is saying this snow's likely to turn into a blizzard," The principal says out in the hall, "you might want to get headed home soon. I'm locking up the front already, and then I'm going to head out too. Have we heard from Mr. Winchester?"

"I'll have Dean call his father to come and get him, but I'll wait with him until then, if you'd rather get home." Casey tells him, because he has a wife and two daughters waiting for him at home, and she's taking a perverse enjoyment at the idea of being the only one in the building with Dean, even if she'd never take advantage of it.

"Alright. Thank you Casey, have a wonderful holiday." And with that, he's retreating back down the hallway to his office, where the lights are already off, and leaving her to go back into the classroom with Dean.

He stands up like he's ready to get out of there the second she's back in the room, but Casey shuts the door and tells him to sit back down, irritation rising up at his presumptuousness. "Did I tell you it was time to leave? Your detention is not over until I say it is."

Dean grins, like he knows he's getting to her, but he sits back down at the desk, kicking his feet up onto the fake wooden top. It's annoying, but honestly, she's going to drive herself crazy if she doesn't just ignore him, and she knows it. Instead, she sits back down at her desk, re-adjusting her glasses before going back to her book. It's boring, but it's better than looking at Dean eye-fucking her over the desk and entertaining the notion of what might happen if she were to return it.

It's sad that she knows better than to try and tell him off at this point, and has accepted that he's going to look. But that doesn't mean she'll give in to it.

A few minutes later, Casey sees Clark's car pulling out of the white parking lot and realizes that she's been staring out of the window for the last few minutes. Dean clears his throat, and she looks back at him to see him stretching, shirt riding up a bit as he leans backwards with his hands behind his head like he's at home. "You know," he says, still grinning, "If you wanted to get me alone, all you had to do was ask."

His eyes are predatory as he leans forward, sparkling with unhidden desire, and he worries his lower lip with his teeth in a way that's much sexier than any teenage boy should be able to manage. Casey feels her heart rate pick up, and it's like she's paralyzed, because Dean slips out from behind his desk and makes his way to the front of the room, and she doesn't say anything.

Dean comes up beside her desk, and Casey dares to tempt fate by swiveling her chair to face him. "You want me, don't you Casey?" And that's another thing she hates about him – he's always calling her by her first name, no respect, but he looks surprisingly respectful as he reaches behind her to snatch her hair clip out.

"Not enough to risk my job," she assures him, "get back to your seat Mr. Winchester." But she doesn't move, and she didn't deny him, even if she's a bit scared to call him by his first name, because it's pretty obvious where he wants this to go, and maybe that will discourage him.

"Please, call me Dean," He chuckles, a gentle palm on her cheek as he eases her glasses off too, placing them on top of her desk with the hair clip. "and baby, I don't kiss and tell." Casey thinks about it quickly, and realizes that yeah, all of his exploits have been shared by the girls themselves. She's never heard Dean say a thing about the things he's done, but it's always been implied in the heated gazes and easy confidence that he knows his way around a woman. And now this is getting out of hand, his hands sliding down her arms and sending shivers across her skin.

"You're seventeen, and I'm your teacher," she protests, but it's still not a no, because she can't bring herself to say it, hoping she can dissuade him some other way for the same reason she took such a sick pleasure out of being alone with him in the school.

"And you're twenty four," Dean replies easily, and he slips his hands up along her sides until he's cupping her breasts. He gives them a gentle squeeze, but doesn't break eye contact, and Casey feels herself starting to get wet at his forwardness. He's unashamed and unrepentant, a challenge in his eyes that she desperately wants to take up. But she knows better. "Besides, soon as this weather clears up I'm gone, so you're not my teacher anymore. Might as well take advantage of it."

Her breath is coming a bit fast, but she hasn't said yes yet, for all that Casey's failed to say no. "You're moving?" She asks, wondering how different class is going to be without Dean sitting there in the back row, making fuck-me eyes at her while she's trying to teach. It's impossible to deny that she's been wearing shorter skirts and higher heels for that exact reason, not to mention lingerie he was never meant to see.

"Yep. We move a lot for my dad's job. This time next week I'll be all the way across the country." It's got bad idea stamped all over it, but Dean's fingers are unbuttoning her shirt already, nimbly pulling it apart to reveal the lacy red bra that does nothing for her modesty. Screw it, Casey decides, as Dean fondles her chest with a practiced ease, fuck him or forever wish you did.

He flicks one of the barbells going through her nipples, grinning up at her with a mischievous expression. "Didn't think you were the type," he says, looking impressed, "I like them." But that's not enough for Dean obviously, because he dips his head to her chest a second later, sucking at the piercing through the lace. Between the heat and the wetness from his mouth, and the slight scratch of the lace as he tongues her nipple, it feels amazing. Casey lets her head fall against the back of her chair, letting out a soft moan of encouragement.

"Gorgeous," Dean agrees, switching his focus to the other nipple, and the air is cold against her skin where his mouth used to be, her nipple pebbling up even further. His fingers dance along her skin, and she arches her back into his touch, gripping her armrests like her life depended on it. Dean unsnaps her bra before she even realizes what he's trying to do, and then he's pulling back, helping her off with the shirt and the bra alike.

Not wanting to take advantage, Casey hesitates, fingers tangling in the hem of his shirt. Dean just grins some more, raising an eyebrow like it's a dare. Fine. Casey can work with that. She pulls his shirt up, strips him of it, and her mouth waters when she sees the hard lines of muscle beneath it.

But then Dean's hands are on her hips and he's backing her up against the side of her own desk. Casey goes with it, mentally sizing up the jean-clad bulge pressing into her, and she really shouldn't be, but whatever, they're doing this, time to stop worrying. She lets him position her so she's perched on the edge of the desk, and then his mouth is on hers.

Dean tongues inside like he owns her and that thought alone is more than a little hot. He's everywhere – a hand on her lower back keeping her pressed against him and supporting her like a gentleman while his other hand twists its way into her hair – hot and possessive. "Thought about this every day in your class," Dean growls, suddenly at her neck before he's biting down hard.

Casey gasps for breath, tensing up slightly, but the hand in her hair is preventing her from denying him her neck, and so she goes with it, arching her back even further and gripping the edge of the desk so hard her fingernails are digging into the wood. "Knew you'd be just like this." The hand in her hair vanishes, and all of a sudden he's pinching her nipple between his fingers, rolling it gently as she gasps. His voice is like liquid sex, low and gravely already.

"F-fuck, Dean," She manages. To hell with trying not to take advantage, he's perfectly aware of what he's doing. Casey releases the desk from her death grip and grabs Dean by the back of his neck instead, pulling him back to her mouth. They're doing this alright.

She battles him with her tongue briefly before letting him into her mouth again, biting down on his lower lip when he withdraws. He gasps out a breath – fucking finally – and Casey lifts her legs up, wrapping them around his waist to pull him closer, her black pumps peeking out from behind him sexily.

"Yeah, right there." He moans, rocking forward against her, and it's in just the right place. And then Dean's dipping his head back to her breasts, planting rough kisses against her skin before sucking a nipple between his teeth once more.

"Oh yeah," She tells him, forcing his head down further with her hands gripping his short hair, and Casey figures her nails are probably digging into his scalp, but he doesn't protest, toying with the metal bar using tongue and teeth. His other hand slides across her stomach, but Casey doesn't even have time to feel self-conscious about it – the position she's in, she's probably got a bit of a muffin top from her skirt digging into her stomach – before those same searching fingers are dipping between them, rubbing her through the matching panties that she put on just for him and he was never meant to see.

It's honestly that kind of self-sabotage that got her into this mess, not that Casey's anything but past caring at this point. "Oh god," she moans, because Dean's surprisingly gentle with the circles he's pressing into her clit, and it's not nearly enough, "more,"

His fingers press in harder, and she can feel the pulse of blood in her crotch with his motions, and Casey's wet and needy and exactly where she knows he wanted her. "Dean," she tells him, yanking his head back from her chest, "dammit, fuck me."

The teenager's eyes sparkle with the knowledge that he's got exactly what he wanted, but he looks just as disheveled as Casey feels, so at least there's that. His fingers pause in their ministrations, and that's enough to make her want to scream, but he simply pushes her skirt up further, hooking a digit under the side of her panties to tug them down.

And then he gets on his knees, presses a kiss to her inner thigh and tugs them the rest of the way down with his teeth.

Dean presses wet, open-mouthed kisses to her leg all the way back up, and he looks like he's going to go all the way with it – of course this kid would, oh god – but Casey stops him, tugging him back to his feet with where she's still got her hand twined into his hair. Her fingers are on his zipper a second later, all the excitement of unwrapping a present for Christmas pooling in her stomach as she frees his cock.

He's gone commando of course, because he's trying to do her in – it's really the only explanation that makes sense, because why else would someone got commando in fucking ten degree weather – and Dean smirks at her again, his cocky attitude coming back to the surface as he tugs a condom out of his back pocket before letting his jeans fall.

"Merry Christmas Ms. Bates," He teases, and Casey tugs him forward, attacking his mouth with hers again just to shut him up. That's wrong, it's so wrong, but it's sending tingly feelings up and down her spine and she can feel him rolling the condom on between them, because, oh fuck, they're doing this.

"Now is not the time to learn to address me as your teacher," She pants out, meaning, get that thing in me like yesterday, because the forbidden-ness of what they're doing shouldn't feel this good.

Obviously Dean understands the sentiment, because he's got one hand on her back again and he's lining himself up with the other, and Casey takes the opening as an advantage to let go of his hair, her hands trailing down his neck to explore the rest of her student's body.

She tightens her grip on his shoulders, fingernails digging into his skin again as he thrusts in, filling her all the way up in one go. He's not hesitant in the least, and Casey tilts her hips up into it, because yeah, he obviously knows what he's doing. She winds her legs around him again, flexing to bring him in even deeper and smiling at the little grunt of pleasure that escapes him.

"Right there," She agrees, panting it into his neck and clutching at his muscular frame as Dean sets a rough pace, holding her to him as he fucks her like he means it.

"Yeah, make it so good Case," he agrees, dipping his head to bite her neck again, and she cries out in pleasured agreement, "Been wanting you all year, know you have too."

"Fuck you," She protests, reaching behind her blindly to grab the ruler off her desk and brandishing it at him, feeling like she should at least put up a bit of a token protest.

She drops it with the motion of another hard thrust from Dean, and he chuckles, panting out a, "got it covered," in response. Cheeky bastard.

"Oh fuck yeah," Stuff is falling off of her desk with their motion; she can hear it hitting the floor behind her, but Casey's past caring. "C'mon Dean,"

There's a scraping noise, and oops, that would be her desk sliding backwards a few centimeters as Dean picks up the pace yet again, hips snapping against her so hard his balls are smacking her ass. Casey giggles – honestly giggles – a bit as she decides to ignore it. She'll never be able to work at this desk again and the thought is surprisingly hysterical.

But then Dean's got his damn talented fingers easing back between her legs, rubbing up and down over her clit roughly in time with his thrusts, and that shuts Casey up pretty fast, opting to gasp for breath instead. It's so good, so good, right there and she can feel her orgasm start to peak, building and building and building up in her with every stroke-snap.

"Case," Dean stills, and she can feel the heat deep inside her as he spills into the condom, but his fingers don't stop moving, and oh god that's it –

"Dean," she cries out, orgasm washing over her like a tidal wave. She clings to him harder, every muscle in her body tensing up and pulling him even closer. He seems to have the same idea, his hand shifting to her hip and the hold bruisingly tight as he rocks back and forth a few more times, forcing aftershock upon aftershock upon her, or maybe a second, third and fourth orgasm – honestly, Casey's lost count, not like she was keeping it to begin with.

"Best night of my life Winchester," she laughs softly to herself, echoing all of the obnoxious sluts she's overheard in the bathroom here a million times, because isn't that the truth.

"What?" Dean chuckles, sounding much more amused than he should have any right to be.

"I asked you if you needed a ride home, Winchester." She covers, glancing at the window they've completely fogged up as he strips off the condom and knots it. It's completely white outside, and she really doesn't want to get stranded here by waiting for his dad. Oh god, his dad…

"That'd be great actually," The smile is genuine for once, "My dad's still out of town, so I should probably get home to Sammy before he starts to worry." And no wonder he's so much more mature than all of the other guys his age – she's seen him taking care of his brother, and it's probably his one redeeming feature.

That, and the mind-blowing sex.

All in all, Dean's certainly not going to be a student Casey forgets anytime soon.