So I felt like writing a KakaSasu one shot, little bit rusty as I haven't written anything in ages but yeah, this is AU school life yaoi. Please don't read and flame if you don't like Yaoi or KakaSasu.
DISCLAIMER: Kakashi Hatake and Sasuke Uchiha are not my creations and all character credits go to Misashi Kishimoto.
WARNING: This fanfiction is hardcore Yaoi. It contains Lemons (sex) smut, swearing and graphic adult material.

Enjoy Perverts.~ ;)

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The tick of the clock seemed to be agonisingly slow today, more so than usual. Sasuke Uchiha glanced down at his finished essay and idly began making a few needless annotations and 'corrections' which were in fact deliberate mistakes. Sasuke was top in all of his classes, English literature was a breeze, particularly when studying Shakespeare, Sasuke knew 'Macbeth' inside out and they were only half way through the semester.

Finally the shrill school bell sounded and thirty chairs suddenly squeaked and scraped across the lino as students got to their feet and grabbed their bags, eager to leave the classroom and start the weekend, last lesson on a Friday always irritated Sasuke, everyone was always so hyped up and excitable and didn't take anything seriously, he cast his peers a glare as they all shoved and pushed their way through the door, chatting excitably about the inane things they had planned that evening… then, his dark eyes flickered forwards to the large pine desk at the front of the English classroom, there sat their teacher, Kakashi Hatake, as usual he made no attempt to calm his students or tell them to stop running like so many did in vain, though he did mention something about their essay being due in Monday, no one but Sasuke seemed to hear.

Once the classroom was empty, the raven haired teen approached the front desk and pulled his bag over his shoulder, anxiously tugging on the sleeve of his school blazer.
The silver haired man looked up from the book he was half heartedly marking, raising an eyebrow at Sasuke.
Kakashi was an odd man, he was quiet and reserved with a dry sense of humour, despite only being in his late twenties his hair was silvery grey, he was a smart dresser and always wore a suit and a green tie and a black mask over his mouth and nose, there were numerous rumours about this mask, some said he had hideously disfigured teeth, others said it was hiding a gnarly scar across his mouth… even Sasuke was intrigued to know what was hidden behind there.
"Yes? What's up Sasuke?" The teacher asked, putting down his pen as he leant back in his chair to look at his pupil with a tilt of his head. "Have you finished that book I gave you already?" The silver haired man grinned behind the mask. Sasuke was clutching a copy of 'The Catcher in the Rye' to his chest, he bit his bottom lip and glanced down at the book before setting it down on the desk, ignoring how clammy his palms were… he always got this way when he and Kakashi were alone. "Yeah… it was okay I suppose…I finished it on Wednesday." Sasuke replied, re-folding his arms across his chest. Kakashi gave another chuckle and shook his head as he put the book back in his desk drawer.
"Well- it's not to everyone's taste, would you like another?" He asked pleasantly, but to his surprise, Sasuke shook his head. Kakashi had given Sasuke a novel to read every Friday since he first started teaching him in September, this was the first time he'd turned one down, he gave Sasuke a quizzical look.
"I actually came to ask-… for extra tuition, I'm really struggling with this Macbeth essay Kakashi…" Sasuke told him but received a warning look from the teacher.
"-Sensei." He corrected himself with a quick roll of his eyes and handed Kakashi the deliberately bellow par Essay he'd written during the lesson.

As Kakashi's steely grey eyes scanned the essay, one silver eyebrow rose in surprise, he lowered the paper and his eyes met Sasuke's, "Sasuke… do you think I'm an idiot?" He sighed and put the fake essay on the desk before getting to his feet, as he did so, Sasuke took a reflexive step back and gripped the strap of his bag a little tighter, pursing his lips as he tried to keep a composed expression, though he broke eye contact and glanced away, remaining silent as Kakashi came to perch on the opposite side of the desk with his ankles and arms crossed.
"Every single essay you've turned into me since the start of the semester has been flawless, you're getting A*s, I know that you've already finished reading Macbeth, along with the novels I've been giving you… so what's with the fake essay?" The teacher was sharp, nothing got past him, least of all Sasuke… he'd known him since he started high school, though only this year was he finally teaching him, he was the smartest kid Konoha high had probably ever seen and Kakashi couldn't deny he was somewhat taken with him.

Sasuke began looking at anything but his teacher, his eyes flickering around the room as he searched his brain for an intelligent reply but he was pretty lost for words, he should have known his teacher would have seen through his poor attempt at idiocy, the mistakes were pretty transparent. The more he tried to think of a reply, the more conscious he became of the silence between them, and it became more difficult to actually think of something to say.
"I uh-… I just wanted some extra tuition sensei." He murmured under his breath, allowing his dark onyx eyes to meet the older man's.
Kakashi smirked weakly and glanced down at his folded arms, shaking his head again as he let out a soft exhale.
"Sasuke…" His tone was different now, the authorative and professional teacher like tone replaced by a more gentle and friendly one. "-I've seen you looking at me in class… no other pupil spends as much extra time doing assignments and coming to study classes as you do… you have a crush on me."

It took precisely three seconds for Sasuke Uchiha's skin to turn from a pale creamy colour to bright puce, his brooding eyes suddenly widening and his knuckles went white as he gripped his school bag and opened his mouth to deny it… but he couldn't. He really wanted to, but the words ceased to formulate on his tongue. Having a crush on a teacher was one thing, but for a guy, to have a crush on a guy teacher was just humiliating, not to mention wrong. Kakashi was such a cool guy no one at school seemed bothered that he was an out of the closet homosexual but Sasuke's feelings had been apparent from his first day of High school, every time Kakashi spoke to him his stomach churned with butterflies, his chest tightened and his head felt light and dizzy as it was right now. He wanted to run and never look back, but it appeared his feet were frozen, along with his tongue, so he just stood there gawping like some deranged goldfish.

Kakashi watched the raven's bashful reaction and couldn't help but smirk, luckily his mask concealed it, he stood up from the desk he was leaning idly against and slid off his tweed blazer before placing a comforting hand on his blushing pupil's shoulder, feeling Sasuke tense beneath him.
"It's alright…" He reassured him, but his eyebrows furrowed, who was he kidding?
"Well-… it's not alright, you're seventeen… I'm your teacher." He told him firmly, to which Sasuke frowned and took a further step back, away from the man's touch, his body language suddenly becoming very reclusive.

"So what? It's… not like anything could ever happen-… I'm not asking it to, I just wanted to-…" He stopped talking then and glanced down at his polished school shoes, shuffling awkwardly on the lino.
"Besides… it's not like you even like me back is it? So…" He added under his breath.
Kakashi made an irritated tutting sound, now it was his turn to look away. "I-… didn't say that, exactly." He mumbled back, awkwardly scratching the back of his head.
Sasuke snapped his head up to look at the elder and his eyes widened a little, his face returning to its normal shade, apart from his cheeks which were still pinched pink. "You… do like me, sensei?" He asked stiffly, not really knowing what to make of this development.
Kakashi looked a little pained then and stared firmly at the door, his arms still folded.
"You're a very talented young man Sasuke…" Was all he replied.

It irritated Sasuke that his teacher was being so coy with him, what was the point in saying that? It achieved nothing…
The teen turned towards the door to leave, knowing nothing could come of this. Just before he turned the handle though, Sasuke paused and glanced back over his shoulder.
"Why can't anything happen? It's my final year of high school… and I'm eighteen in July." He told Kakashi, and realised he sounded like a spoilt little kid at that point and instantly resented it.
Kakashi made a muffled groan and ran his hands through his hair, his brow furrowing with the stress as he began to pace the classroom.

"Because, Sasuke-… it'd put my job on the line, it's unprofessional, not to mention illegal, you're under age…believe me, it's tormenting, seeing you every day, in that uniform." Kakashi's voice took on an odd tight quality, as if there was something stuck in his throat, Sasuke blushed yet more furiously as he watched his teacher loosening his tie… he glanced down at said uniform and nibbled his bottom lip, his hand still poised on the door handle. He wasn't going to leave things like this, Kakashi couldn't say things like that and not expect a reaction, and it was as if he was deliberately baiting him.

Impulsively, Sasuke threw down his school bag and swiftly crossed the room, shoving his teacher back against the door of the store cupboard, before Kakashi could react, Sasuke had reached up and yanked down that black mask Kakashi used to cover his face and took a second to glance at the flesh it revealed beneath, needless to say, Kakashi's lower face was as perfect and handsome as the rest of him, goodness knows why he kept features that sexy covered up. Before he could stop himself, Sasuke leant forward and broke the distance between them, crushing his mouth against his teacher's in a fierce but slightly nervous kiss.

Kakashi stiffened on feeling Sasuke kissing him, it took all his self control to grip the boy's shoulders and push him back, staring at him wide eyed. Had Sasuke really just uncovered his mouth and kissed him? He was the first person, ever to have managed that…he parted his lips a little and stared at the shorter male who just stared right back, the silence between them was torturous.
"S-Sasuke…" The elder hissed through gritted teeth as he had some sort of moral dilemma with himself…
The raven was about to apologise when he felt Kakashi's lips on his again and he froze, his head suddenly spinning and his gut churning, he was being pushed against the door now, Kakashi's warm, masculine form was pressed against him and they were kissing, both their lips locked together in a deep and fierce kiss.
Sasuke felt himself melting against the other man's mouth and his arms slowly snaked up around his neck to press himself yet closer. He felt a soft groan come from his mouth as his teacher's tongue forced its way into his mouth.
Sasuke allowed his eyes to close as he became lost in the heated embrace, it was just how he'd pictured it, sensual yet passionate. He could tell how experienced the older man was by the dominance of the kiss and the way his tongue slithered around inside his mouth.

As the kiss developed, neither of them seemed to want to break away, running their hands over each other's bodies as the sound of their tongues locking as they made out filled the empty class room.
Suddenly Sasuke felt Kakashi's knee push between his legs, forcing them apart so he could grind it against Sasuke's crotch. The raven squirmed against the door and made a muffled groaning sound at the friction, already semi-hard from their kiss… "Sensei..." He whimpered helplessly as his whole body became a thousand degrees hotter, Kakashi groaned lustfully at the sound of Sasuke's young voice moaning that word and pressed his knee more firmly against his manhood, earning another wanting moan.

Shyly, the young pupil reached down between them to cup the older man's crotch, he was surprised at just how hard he was down there, Kakashi arched his throbbing, clothed erection against Sasuke as they kissed and Sasuke gave it a nervous squeeze.
Kakashi couldn't hold back anymore- he'd wanted this for so long, and denied himself the opportunity. Quickly and effortlessly Kakashi picked up Sasuke so his legs were linked around his waist and moved over to his desk which he threw the teenager down on without breaking the kiss. Sasuke groaned as his back connected with the wood and suddenly, his teacher pulled away, panting and glistening in sweat. The older man tore off his tie and shirt and reached for a set of keys to quickly lock the classroom door.

As he watched Kakashi across the room, Sasuke had a moment to breathe and… well, think… were they going to have sex? Sasuke really wanted to, he'd thought of nothing else since Kakashi started teaching him. He shrugged off his blazer and began to loosen his tie when Kakashi ceased him. "Leave this on…" The older man smirked, like some sex crazed beast he had a lustful look in his eyes.
"I want to fuck you wearing your uniform." He purred into Sasuke's ear as he began undoing his flies, allowing his pants to fall round his ankles, revealing his enormous appendage. Kakashi seemed to have abandoned all of his morals and self control whilst they were kissing, all he wanted now was to make his student moan as he fucked his ass. Sasuke leant up on his elbows and watched Kakashi, his stomach churning in anticipation. He was about to remove his own pants when Kakashi beat him to it, pinning Sasuke's chest to the desk with one hand and yanking his trousers undone with the other and pulling them down.
Sasuke blushed as his now rock hard cock was visible, dripping pre-cum all over his stomach, his heart was pounding now as Kakashi loomed over him with an animalistic expression on that flawless face. All Sasuke could do right now was lay back on the desk and gaze up at his soon to be lover, butterflies began to swarm in his gut as Kakashi lifted his slim pale legs onto his shoulders and pushed his dark hair back from his clammy forehead.
"Are you okay? You want this-…right? You've… had sex with a man before?" Kakashi asked him in a husky purr, Sasuke could just about manage a feverish nod and leant up shyly to kiss him.
He'd never had sex before, but he wasn't going to tell Kakashi that, if he was going to lose his virginity, he wanted it to be to Kakashi, his teacher who he'd been in love with since his first day of high school.

Sasuke watched through half lidded eyes, his chest heaving as Kakashi reached into his top drawer for a tub of Vaseline… perhaps it wasn't his first extra-curricular activity in the classroom. Kakashi skilfully unlidded the pot and took a big scoop which he smothered all over his cock, watching Kakashi stroking his huge length made Sasuke squirm with anticipation, though he was pretty nervous, Kakashi hadn't prepared him at all and… he was really big. But still, Sasuke remained silent and wrapped his legs a little tighter around his sensei as Kakashi lubed himself and positioned the tip of his dick against Sasuke's tight, puckered entrance.
The young raven took a deep breath and leant up from the desk, crushing his lips against the others so he wouldn't notice how much he was shaking. Kakashi gripped Sasuke's thighs and with one firm thrust of his hips he pushed his slippery length inside Sasuke, filling him instantly and making a choking sound at the tight heat that engulfed his manhood.

Sasuke had never experienced such intense pain before in his life, his whole body suddenly ached in agony as he felt Kakashi's solid cock pushing into him, causing him to arch violently off the desk, forcing him to break the kiss. Small, pale hands, curled into fists on the desk and Sasuke grit his teeth hard to suppress the loud groan that left his throat, he was fighting back the urge to scream and held his breath as he endured Kakashi filling him, tears brimmed in the corners of his eyes and trickled down his burning cheeks.
Meanwhile, his experienced lover groaned with pleasure and cursed under his breath, gripping Sasuke's thighs as he peered down at the student he was violating… by his reaction, Kakashi could tell instantly that Sasuke was a virgin and he mentally cursed the boy for lying to him… still, he was so insanely tight and hot, there was no way he could stop now. He decided to lecture Sasuke later and slid his right arm under his back a little to lift him closer, now he was balls deep in the Uchiha, Kakashi stroked his dark hair from his face and kissed him softly. "Relax… Sasuke…" He whispered against his lips.
Sasuke focused on the kiss, rather than the pain in his rear and began breathing slowly and steadily, clinging a little tighter to Kakashi's toned upper body.

As Sasuke began to adjust to the huge intrusion, he realised just how heavenly it felt to have Kakashi inside of him, how wonderfully full he felt and every part of his insides tingled with pleasure, Sasuke dared himself to thrust his hips up a little and gasped when he felt Kakashi's tip push against his g-spot, the most intensely pleasurable sensation he'd ever experienced before caused his eyes to re-open as he kissed Kakashi more fiercely… it felt so damn good, despite the dull pain aching in his back, he wanted Kakashi to move, and fuck him hard. "M-move.. I'm okay… j-just fuck me." Sasuke moaned needily into his lover's mouth and Kakashi groaned appreciatively, Sasuke's words making him increasingly horny.
Leaning over the desk a little more, the silver haired teacher began to thrust his hips, nudging his tip against Sasuke's g-spot, it was so suffocating and tight inside him he could barely move, but soon enough, Kakashi was thrusting his length in and out of the teen at a firm steady rhythm.

At first, Sasuke desperately tried to keep his mouth shut to muffle the embarrassing noises he was making, but every thrust titillated him more than the last and eventually he submitted and allowed his head to fall back a little in Kakashi's arms and soft moans to pour from his mouth, becoming louder and whinier as Kakashi thrusted harder and harder. "A-aahn… S-sensei… mmngh…" He moaned as Kakashi built up rhythm, forcing his eyes to stay open so he could gaze at his teacher.
Kakashi watched Sasuke's heavenly reactions and it only spurred him on to fuck Sasuke harder and faster, laying him down on the desk properly now, Kakashi took hold of Sasuke's skinny ankles and held them up, spreading the teens legs wider which allowed him to plunge his cock deeper and deeper inside Sasuke. "Nngh… Sasuke…" He groaned, already his body was glistening in sweat and his hair was damp. He gazed down at the mess he was making of his pupil, still wearing his school shirt and tie, he noted his neglected cock now swollen and fit to burst, soaking his shaft with pre-cum, the image made Kakashi smirk and he reached down to wrap his fingers around Sasuke's cock which he began stroking.

Sasuke mewled as he felt Kakashi begin to jerk him off… he threw his head back, along with his arms and gripped the desk above his head, keeping his legs spread as wide as he could so Kakashi could fuck him hard and deep… every time he felt his sensei slam against his g-spot, his hand tightened around his cock too, bringing Sasuke closer and closer to climaxing. He squirmed on the desk and whimpered and moaned, unable to deal with this much pleasure, Kakashi was really making a mess of him.
"Aah! Harder! Harder!" Sasuke yelled as he became desperate for more, gripping the desk so tight, his knuckles flashed white. Happy to oblige, Kakashi sped up his thrusts and slammed his dick mercilessly in and out of the young boy, groaning as he fucked him harder and harder, jerking his wrist and fisting Sasuke's cock as he did so. Sasuke was all but screaming now, his face bright red as he arched up from the desk which was now being jerked back and forth noisily. Everything suddenly got very intense, the sounds of the desk, alongside their flesh smacking together, Sasuke's screaming desperate moans and Kakashi's groans of pleasure as the two of them made love.

Sasuke could barely take this anymore, the searing pleasure in his cock was too much and he suddenly slammed his hand onto Kakashi's to stop him, shaking his head frantically. "N-nuh…mm… stop-… I'm gunna ah!" He whimpered suddenly and slammed his eyes shut, forcing himself not to cum.
Kakashi smirked as he sensed the Uchiha's desperation to fight his orgasm and suddenly pulled out of Sasuke with a loud squelch, causing the Uchiha to cry out in alarm. Sasuke looked up at him with confusion on his face, and whined feebly, his body buzzing with the sensation of being about to orgasm when it was suddenly ceased. Kakashi turned Sasuke on his side on the desk and lifted one of his legs over his shoulders, leaning down to kiss his student hungrily before firmly pushing his cock back inside of him with a throaty groan.
"Mmnh-… Kakashi…" Sasuke whimpered and wound his arm around Kakashi's neck as they kissed and Kakashi began fucking him again, instantly the pleasurable sensation returned and soon Kakashi was fucking him just as hard and fast as before, pounding him sideways now on the desk. "Nngh Sasuke… you're so tight…" Kakashi groaned into Sasuke's ear and kissed his neck and exposed collar bone… he was trying to hold off but he wouldn't last much longer, the fire in his gut was intensifying as his cock slid in and out of the younger male faster and faster.
"I'm close-… cum for me Sasuke…" He commanded and reached down to squeeze his lover's dick.
Sasuke whimpered and arched violently as his eyes snapped shut, he pursed his lips and shook his head, unable to deal with the powerful orgasm which was brewing in his gut. "Mmnh-… n-nn… aaah! AH!" He suddenly screamed out, his whole body thrown into a spasm of mind numbing pleasure as he came hard. Hot, white seed exploded from the tip of Sasuke's cock, drenching his school shirt as he shuddered violently, moaning feverishly with Kakashi still fucking him without restraint.
Kakashi sped up his thrusts suddenly and began to pant and groan, then with one final slam of his hips, he threw his sweat soaked head back and came hard inside his young lover, filling him up with a huge load of cum which spilled out and trickled all over the paperwork beneath them.
He held himself inside Sasuke, thrusting weakly as he spilt his load and released Sasuke's leg, allowing it to fall limply against the other.

As their orgasm's subsided, both males made eye contact and just lay there, panting feverishly and gazing at each other… Very gently, Kakashi pulled himself out of Sasuke, hushing him as he whimpered at the sting it caused. He used what little energy he had left to lift the school boy into his arms, sitting back down in his teacher's chair with Sasuke's limp, spent body in his lap, he slipped his arms protectively around his skinny frame and planted a soft kiss on his forehead, still panting and seeing stars after that earth shattering orgasm.
Sasuke was still pretty out of it, his head spinning and his whole body aching and jelly like.
The Uchiha curled into a foetal position in his sensei's lap and rested his head over his heart, just listening to the sound of his pounding heart and laboured breathing… after a few minutes, he glanced up to examine Kakashi's handsome face.
Kakashi felt his eyes on him and glanced down at Sasuke's cutely flushed face and smirked helplessly, stroking his messy hair.
"You okay?" He whispered gruffly, his throat scratched from groaning.
"Mmn… yeah… hurts though." Sasuke mumbled back into his chest and felt himself blush as he noticed his teacher's semen dribbling out of his butt all over Kakashi's legs.
"Serves you right for lying about being a virgin." Kakashi smirked and Sasuke cringed, was it that obvious?
"I-… hn… I thought you'd stop if you knew…" Sasuke defended himself and narrowed his eyes at his teacher a little. The smirk remained on the man's face and he shook his head. "How could I?" He chuckled. "I just… would have prepared you first. You're going to be in agony tomorrow." He warned his lover and kissed his lips gently.
Sasuke smiled weakly, he didn't smile often, if ever… but he did now, because for the first time in ages, he felt truly happy, in Kakashi's arms, just the two of them… he liked being his teacher's dirty little secret. "S'worth it…" He whispered back sleepily and leant up to kiss his lover's lips, laying a hand gently on the side of his face, it pleased him to know he was probably the only one in the entire school to have seen Kakashi Hatake's perfect face beneath that mask.
"You know… Sasuke?" Kakashi broke Sasuke's train of thought and tilted his chin up to look at him.
"I think-… extra tuition after school is a good idea… perhaps we should make it a regular thing?"

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Hurr… that's the first fanfic I've written in years. xD
Random little one-shot there~ I've never written KakaSasu before either come to think of it. Anyway- hope you liked it.
Reviews and constructive criticism would be greatly appreciated.