A/N: Serina is one of my favourite characters in the game, I'd wager. She's so sweet and wholesome, and also a useful in-game character too.

Do enjoy~

Don't Wake Hanae

Christmas was less than a week away.

Given that, Sensei had been quite busy – putting aside the various events he'd been invited to and the various bundles of chaos he had to handle, he also had various students who came vying for his attention. As their teacher he did his best to not appear biased towards any one school, dividing his time as consciously as he could.

But in truth, even if he'd only ever say it to himself, he did have a favourite student. Serina. The pretty, pink-haired medic who seemed to have a habit of stalking him in her free time, always ten steps away from being by his side and ready to treat even the most minor of headaches. He made an effort to visit her the most out of all his students, spending his time with her liberally, and in time that closeness became something much more risqué than mere teacher-student closeness.

And as such, when she invited him out along with Hanae to deliver presents, he gladly obliged.

It was hard work, but delivering presents to a bunch of old dogs – literally and figuratively – was a very wholesome experience, especially with Serina and Hanae by his side.

With the fall of night though the time for delivering was over, and with gratitude he accepted Serina's offer to return to her dorm in Trinity.

''Haah~ It's so cosy in here~''

''Hehe, I set the thermostat up before we left~''

Sensei smiled warmly as Serina and Hanae chatted; the latter quickly depositing her now-empty bag of presents on the floor and hurrying over to the kotatsu – shuffling under it and flopping down against the table with a sigh of relief.

Serina's room was quite the cosy one, both in temperature and in design. Divided between a small living room and equally quaint bedroom it almost had an apartment feel to it, the ivory walls dotted with pictures featuring various landscapes, scenes or more often her friends. A couple bookshelves held various books and trophies whilst the tiny kitchenette was polished to a shine, not even a speck of dust to be seen upon it.

The sole window in the room revealed the night outside until Serina meandered over and pulled the blinds closed, humming merrily. ''Would you like some tea Sensei?''

''Sure.'' He acquiesced warmly.

Serina chirped a merry 'okay~' back at him, pulling out some mugs and setting the kettle on to boil. Sensei meanwhile shed his thick red jacket and hung it up on the back of her door, idly removing his shoes before making his way over to the kotatsu in the middle of the room, sitting down and shuffling his legs underneath. The warmth only lured him in, a profound sense of calm washing over him then and there.

''It's nice, huh~'' Hanae must've seen his expression, giggling.

Sensei hummed and bobbed his head, gazing over at the purple-haired girl as she laid her head on the table, humming to herself as she awaited her own mug of tea. She looked cute in her Santa getup; the thick sweater and twin-tail style she'd put her hair into giving her an innocent charm.

Thinking of her though lured his gaze over to Serina. Much like her comrade-in-arms Serina also wore a Santa dress-coat, the red fabric hemmed by a fluffy white trim like fresh snow. She looked absolutely adorable in it, his eyes slowly wandering down her slim figure and admiring her legs, slender and covered by black pantyhose. He looked away quickly, not wanting to be caught eyeing her legs up like that, but he entertained himself with the thought of caressing them all the same.

Soon enough Serina meandered over, a tray of three mugs upon it. ''Tea's ready~''

Hanae cheered and swiped her mug – one amusingly labelled with her name on it – and chugged a third of it down, apparently unbothered by the steaming hotness of it. Sitting down next to him Serina took her own cup of tea and blew on it first, the gentle motion charming, before she gracefully took a little sip. As she did so she glanced his way, her cheeks gaining a bit of pinkness and her brow furrowing in adorable chastisement, not a syllable said but her intent made clear.

Smiling back Sensei took his own mug and blew on it, feeling the fine ceramic warm his hands up as he took a sip. It tasted of ginger and went down his throat easily – hot, but pleasantly so. After spending several hours trudging through knee-high snow and dragging bags of presents about, it was a welcome reprieve. How Serina and Hanae could do this every year while also keeping up with their studies he had no idea.

Lowering his mug he smacked his lips a couple of times, savouring the sweetish aftertaste. ''Mm... that's quite good. Ginger tea?''

''That's right. I made it myself to help people who felt sick, but I find it's nice to have during winter too.'' Serina earnestly said, caressing her mug as she talked. ''I can give you the recipe if you want?''

''Haha, I'd rather have you make it for me instead.''

''Sensei~'' Serina gave him a light, playful swat on the arm.

The two of them continued chatting, Hanae contributing a few words here and there – but Sensei was quick to notice that those words became fewer and fewer with every passing minute, until soon enough she had no more to offer, her arms crossed and head resting in them.

Serina soon noticed his curious looks and explained; ''Ah, Hanae gets sleepy when she drinks my ginger tea. Don't mind her – she's a heavy sleeper.''

The fact she specified that otherwise irrelevant detail drew his eye. Serina smiled at him, her pink eyes softening and her left hand sliding along the blue carpet, her gloved fingers soon tickling his bare ones. He twisted his hand about so her smaller hand rested in his, squeezing it, and Serina replied by nudging her ginger tea further away. He did the same – but his eyes never left her, watching as his student lifted her butt up and dug her thumb into her black pantyhose before peeling it down her slim, creamy thighs, leaving them just above her knees alongside her white panties.

Before shyly she undid the lower two buttons on her dress coat and lifted it. Without her pantyhose in the way he could admire her bare tummy and groin freely, his eyes roaming over the soft flesh of her thighs and between them too, barely able to spy her lips with her legs together. Solving that Serina shyly opened her legs a little, her head tilting in a silent suggestion – one that Sensei obliged, his left hand sliding over her thigh and down between her legs.

''Mn-'' Serina pursed her lips, quietening her moan as he caressed her pussy. ''Sensei...''

''Ssh.'' Was all he said, pointing with his other hand at Hanae.

Serina understood, her cheeks darkening to the same shade of her hair. He smiled at that and planted a quick kiss on her cheek, coaxing her in and soon letting his lips graze, then peck hers. It was a gentle thing but he steadily deepened it, leaning into her as he savoured those slim, affectionate lips, her free hand caressing his cheek whilst his played with her pussy – stroking her bare slit and making her exhale shakily.

Not satisfied with just that he rubbed her opening, fingers still cold from the outdoors – before pushing two of them inside. Serina squeaked but otherwise kept her voice to herself, her pink blush becoming a rosy one as he wriggled his fingers deeper inside of her – soon scissoring them apart. She pulled away from the kiss but he was quick to claim her again, devouring her adorable whimper as he worked his digits.

Pulling them back slightly he an his thumb over her clit, teasing her, and Serina rewarded him with a quivering little noise from the back of her throat – her eyes flitting to Hanae, worried she'd wake up in spite of her claim of her being a heavy sleeper. Yet Hanae did not so much as stir; snoring away even as Serina let out a string of little moans and whimpers, her warm thighs pressing in against his hand as he toyed with her clit, his fingers too working her up inside.

''S-Sensei...'' Serina whimpered out, her lips brushing his. ''C-Can I make you feel good as well? It's not fair if it's only me, and you used your tongue on me last time...''

The reminder made his pants feel acutely tight and he complied, pecking her lips one last time before shifting back into his seat, his fingers withdrawing from her lips and his hands settling behind himself, supporting his weight. His eyes though didn't leave Serina as his earnest lover shuffled a little closer and eased herself down onto her left side, the position incidentally leaving her head in his lap. A fact that prompted him to unzip his pants and manipulate the button on his boxers.

Seconds later his cock sprung out, erect and eager for her love. Even though she'd seen it many times before Serina still blushed deeply at the sight of it, her bewitched gaze glued to his cock whilst her fingers gravitated towards it, gripping him tenderly and pumping him leisurely – hardly rushing to get him off. Even with Hanae mere feet away, the only thing hiding their lewd act being the table, there was no rush. Better to savour the moment than to rush to climax, after all.

Sensei appreciated that sentiment aplenty as Serina worked her wrist. Leaning back as he was he could look down at his pink-haired lover as she worked, her head rising up and her breath tickling his tip – and he clenched his jaw as she took him into her mouth. It was hot, wet, and ever so inviting; her slim lips pursing halfway down his cock and sucking quietly up to the tip before she descended once more, her motions tentative as if checking to see how much noise it'd make.

''She's still sleeping.'' Sensei murmured quietly, rubbing her back.

Serina hummed – the sound muffled by his cock and teasing his shaft with the pleasant vibrations. Groaning he stared down at the medic, her head of pink hair the only thing he could see as she bobbed it into his groin, enveloping more and more of his cock within her mouth. He glanced up at Hanae again, trying to keep an eye on her, but the sensual blowjob Serina was giving him was impossible to look away from.

Then again her ass was a tempting sight too. Laid on her side he could spy her bare butt and after a moment of gazing he let his right hand wander down, copping a feel and earning a hum from his partner, her following suck especially strong. He returned his hand onto her back at that, rubbing it encouragingly and being rewarded with more quickening sucks, her devotion to him shining through as she cared for his cock with her mouth.

''Hng, Serina, your mouth feels good...'' Sensei murmured as quietly as he could. ''You've gotten a lot better as of, hn, late...''

With a mouth full of dick Serina couldn't reply but the slower, more loving suck she gave his dick conveyed her appreciation all the same – as did the faster sucks that followed. Her lips glided down his cock every second, caressing him between those pretty lips and smearing her spit along them, turning her sucks into arousing slurps. Slurps that felt dangerously loud, his breathing tight as she bobbed her head, her hands clutching onto his thighs as she kept him steady.

He put his hand on the back of her head in response, pushing her deeper. Serina obeyed without resistance, a cute grunt escaping the angel as she went deep – nearly throating him. He could feel his tip graze the back of her throat and pushed her down with every head-bob, his breathing fast and growing moreso as she slurped his cock with a devotion unmatched, servicing him like her life depended on it, lubing him with naught but her mouth.

And then she deep-throated him.

He exhaled sharply, clutching at the carpet even as he kept shoving her down, tension climbing his back and euphoria building in his dick – every potent throb threatening to make him bust. He held back, jaw tense, his eyes flitting between the back of Serina's head or Hanae's sleeping form, his balls tensing-!

And then he threw his head back, hissing as he nutted in Serina's mouth. His hand pushed her down and kept her there, his cock-head poking down her tight throat as he spewed untold amounts of semen down it. She didn't resist. She didn't even flinch away from his hold. With utmost devotion Serina buried her face into his crotch and swallowed every last drop, her gulps slow and pronounced, her lips firmly wrapped around the base so as to assure not even one little bit of his sperm escaping her loyal mouth.

A small, blissfully-hot eternity passed, one punctuated by her slow licks along the shaft – when at last he regained the sense to loosen his grip on her. Serina pulled back slowly, her lips soon popping off of the tip and her hand coming to touch them, keeping them closed as she gulped several more times. When she finally let her hand fall aside she bashfully opened her mouth, showing not even a speck of cum on her tongue. She'd swallowed it all.

''Hah, good girl...'' Sensei half-jokingly praised, petting her back.

Serina giggled sheepishly, wiping her lips dry of spit and looking off to the side, her shyness endearing – so much so he pecked her on the cheek. She kissed him back on the nose but before he could kiss her lips she got a finger between them – shushing him and staring into his eyes for a long, long moment.

''...I've always liked Sensei's eyes.'' Serina whispered, her own pink ones briefly hidden behind blinking lashes. ''...ehe, sorry.''

Sensei just pecked her on the nose. Serina giggled prettily and leaned back, reaching into her dress pocket for a few moments, rummaging – before pulling out a condom packet. She ripped it open with her teeth and offered the condom within to him, her gaze become demure as she shifted down onto her right side, her ass facing him and eyes gleaming with anticipation.

Seeing that, how could he ever resist? Shifting down behind her, his legs under the kotatsu, Sensei unfurled the condom over his cock like a snug-fitting sheath, stroking it into place before rubbing the covered tip against her pussy. The meagre stimulation was enough to make Serina mewl with anticipation, her head lifting as she peeked over at Hanae, but the purple-haired girl remained oblivious in her dreaming state.

Sensei propped himself up on his right arm, using his left to guide him in, her petals parting – and as one they moaned as he penetrated her. It wasn't their first time but Serina was as tight now as she was then, her pussy like a vice that clenched around his intruding girth. He rocked his hips, easing more and more of his sensitive cock inside Serina, loving all the little breaths and whimpers he fucked out of her.

''A-Ahh, Sensei, you're reaching in... s-so deep~'' Serina mewled quietly.

He shuddered at her breathy tone and pressed him in deep, spooning Serina and pushing his hips in short, stirring thrusts, churning her insides up. The stifled whimper it got in return left him drunk on lust, his left hand landing on her groin as he kept her body close to his own, his other coming to rest just under her head – allowing him to bring his lips down to her ear, breathing into it.

''You're so tight Serina.'' He whispered, relishing how it made her tense around his length. ''Mnph, seeing you in this outfit is making it hard to be quiet. You're so damn cute I just wanna go to town on you.''

''But Hanae...'' Serina mewled back.

He kissed her ear, his breath hot and his words husky. ''She won't wake up, just, mn, don't make too much noise okay?''

Serina responded by pushing her ass back into his groin, whimpering for more, and with a grunt in return he pressed into her – his thrusts resuming. Gone were the tender ones and in their place was a string of faster pumps, his cock grazing between her folds and hilting in her tightness, the snug grip of her womanhood only driving him deeper into her – every thrust rougher than the one before it, soon making his groin clap her ass.

The lurid sound of their flesh smacking, of their sinfulness laid bare to those privy, just fuelled his horniness – his groans spilled directly into Serina's ear. The petite nurse always had sensitive hearing and he used that fact to his advantage, letting her hear every breath, every grunt and every moan in acute detail. The effect was made abundantly clear with how she writhed under him, her gasps sweet and her moans shallow but trembling as she struggled to hold her voice back.

''Hnf, I love you Serina, love you so much.'' He kissed her ear as he whispered into it. ''So much so I wanna rip this condom off and be an irresponsible teacher.''

''Do it.'' Serina whimpered. ''I-If it's Sensei I don't mind.''

''Tempting.'' He struggled to get the words out. ''But I don't think I can stop now, hnf... I'm too close.''

''Same.'' The medic squeaked back, hand over his. ''S-Sensei...!''

Their flesh slapped together, the back of her dress coat barely stifling the sound, to the point even he worried Hanae might awaken – but he couldn't stop. His hips drove his swollen cock deep into Serina's tight, receptive pussy, her slick walls letting him practically glide inside and hilt in her gripping depths. The prospect of spilling his load within her womb thrilled him, his groin smacking her ass as he devoted himself to fucking her senseless-!

And then with a hand over her mouth Serina cried out, cumming. Her insides clamped down and he managed only a few thrusts before he busted, hissing out a breath through gritted teeth as he filled the condom with his cum, his thrusts ragged and rapidly slowing as he nutted inside her – the only thing stopping him from impregnating her being the damn condom.

Sensei rocked his hips for a little longer, his hips sore but his lust stronger – until with a low groan he rocked them back further, letting his dick slip out of her. Quickly he worked the condom off and set it down on the carpet, carefully angling it so the cum didn't leak too much, and the moment that was out of the way his hand attended to his cock, massaging and kneading his member. Tender, electrified, yet still semi-erect for her.

A good thing too as Serina rolled onto her back, gazing up at him. The look of breathless love on her face bewitched him and he shifted on top of her, his legs between hers as he pinned her to the floor – and Serina hummed as he claimed her lips in a kiss. It lasted just a few seconds but moments after they broke it off he kissed her again, then again and again – grinding his bare cock along her pussy as he made out with his lover, the stimulation helping get him fully erect once more.

''Serina...'' He breathed against her lips. ''Can I put it in again?''

''Of course.'' The pink-haired angel cupped his cheeks, smiling shyly. ''And... make sure to cum inside, okay? It'd be bad if Hanae was to notice any stains on my dress, right?''

The open request left his cock aching, a primal need to knock this innocent angel up overpowering him – coaxing his right hand down to his cock, guiding his tip along her glistening, sopping petals, dipping down... and then with a unified groan he penetrated Serina once more, her soaking-wet pussy clenching around him once more. The loving grip of her insides was made all the more intense by his sensitivity but he didn't stop until he was balls-deep inside his lover, feeling her twitch and quiver around his shaft.

Propping himself up on his elbows Sensei started slow, peeking over his shoulder at Hanae, but when the Santa girl continued to snooze he dared to get a bit faster – grunting with every thrust as he buried himself inside of Serina. Her narrow pussy felt so good he could see himself cumming easily, but he did his best to endure; his jaw tense as he pistoned into her.

''Ahn, Sensei... doing it without a condom...'' Serina puffed out, covering her mouth with a hand. ''...it feels really good.''

He brushed that hand aside and arched his back, working past the height difference between them and pecking her lips. ''Does it feel good to do this right next to your sleeping friend?''

''...y-yes...'' Serina whimpered out, simultaneously ashamed and undeniably turned on.

He kissed her forehead, grunting as he dared be rougher with her – his thrusts faster, his strokes shorter, his force stronger. Their flesh loudly collided and Serina couldn't hope to hide her whimpers and mewls, so scandalous if someone was to overhear the Remedial Knight, but none did – Hanae remaining blissfully unaware of her comrade-in-arms having baby-making sex three feet away from her.

Serina wrapped her arms around his neck then, pulling him down, and with a groan he obliged – nearly laying on top of her as he hurriedly plunged his cock into her. Her moans tickled his left ear and his own did her right, their closeness only heightening how hot it was, having bareback sex with her friend just behind them. The scandalous nature of it fuelled his mounting orgasm, his cock pulsating within her molten grip, the urge to release his cum inside of her so very tempting.

''Yes Sensei, please, yes, ah, yes~'' Serina panted out, her grip on him tightening. ''I'm almost, cumming, please~!''

His hips slammed forth, pounding her tightening cunt, making her cry out into his shoulder-!

And then with a grunt he emptied his balls inside of Serina, going balls-deep and flooding Serina's womb with his virile seed. Her wet vice clenched repeatedly, coaxing every last drop of cum out of him, his shaft sheathed deep within the angel as he did his damnedest to get her pregnant right then and there, his body drawn taut as he devoted himself to the sinful act.

A small eternity passed, the tension seeping from his muscles, until at last he was able to think once more – groaning and collapsing atop her. Serina didn't protest and just held onto him, snuggling into his shoulder as she caught her breath, the sound of their heavy breathing the only noise about.

Until Hanae started to shift. ''Mn...''

Within the minute Hanae would wake, rising her head and mumbling... and slightly curious about Sensei and Serina, red-faced next to each other as they chatted with unusual enthusiasm about the floor, their clothes askew as if hurriedly pulled into place.

Before Hanae shrugged it off and went to the bathroom, missing the sighs of relief the two would release.

Their risky romp remaining unknown.

At least, until Serina started to show a baby bump a few months later.

[END]