#gravity grandpa touches all of my kinks

[ssigmas]

office hours

hi this is literally the most self-indulgent filth i’ve ever written ever in my whole life its just like all my fantasies wrapped into one big fic

also im not a math major don’t @ me

tags: afab reader, professor/student, age gap, desk fuckin, stockings, first time,  Guilt, professor kink 👀

 Siebren tried not to have favorites. He really, really did. He took pride in his ability to remain as objective and unbiased as possible, especially concerning his students. No matter their walks of life, their intellectual capabilities, or their attitude in his class, he treated everyone fairly and with the same amount of respect.

But you. You were different. You, who always sat in the front row, who always asked insightful questions, who often came by his office just to chat - he considered you less alongside the notions of “student” but closer to “friend.”

And you were brilliant, too - the likes of which he hadn’t seen in a long time. You struggled with much of the math (which is why you started coming to his office at all) but you had an intuitive understanding of the concepts behind quantum mechanics, something most students lacked. They could do the math fine without understanding the real-world significance it held, but you? You didn’t understand why it worked, but you understood the how, and it made class discussions more enjoyable. You often provided another angle of viewing things, and Siebren had been pleasantly surprised the many times it had been an angle he’d never considered before.

His class wasn’t easy - not that he purposefully made it that way, but the subject matter was extremely difficult. The grade you held in his class was a testament to how hard you worked. On top of that, he knew you also held the same work ethic in your other courses - all of your professors had nothing but glowing praise for you.

You were a kind, hardworking student with just a little too much on your plate. Siebren had a hard time not admiring you. He saw a little bit of himself in you, which is maybe why he found it easy to give you preferential treatment. Not when it came to your grades; he graded blindly, so there was no chance that he’d add a few extra points just because it was you, but in other ways.

Like the time you came to his office well past his normal hours with your bag slung over your shoulder and shadows so dark under your eyes he’d mistaken it for makeup. “Please,” you had said, “I-I know it’s late, but can I study in here? The library’s too crowded for me to focus, and my roommate has her partner over and they keep being...gross, and I just… I promise I’ll be quiet, please?”

You had sounded so exhausted and so close to tears that Siebren literally could not turn you away. He knew he’d be there for another few hours before he headed home, so he had ushered you into his office with a kind smile and brewed a fresh pot of coffee. Working with you in his office had been...so nice. You weren’t draining in the way that so many others were, and he had easily fallen into a deep focus on his research, aided by the constant sktch sktch of your pencil against paper and the soft symphonies flowing through his speakers. 

God, when he found out you listened to Schumann…who could blame him for crushing on you?

It made him feel pathetic, honestly. A renowned professor with multiple degrees, teaching at one of the most elite colleges in the nation, crushing on his student? What kind of twisted pervert had a crush on someone more than half his age?

Him. He did. He was a dirty old man with more than “just a crush” on his favorite student, and he couldn’t get you out of his mind.

You were so cute, even on the days you showed up to his 8 am class in nothing more than an oversized hoodie and joggers, coffee clutched in hand. He loved it when you smiled for him, those tiny secretive smiles that made your eyes light up, or when you giggled genuinely at his god-awful puns despite the fact that no one else did. 

The things he imagined doing to you were more shameful than he was willing to admit. Many times he found himself waking with your name stuck in his throat and a problem that he had to quickly take care of. Cold showers, unfortunately, didn’t help him any more than trying to ignore it. As of late he found himself in hand more times than ever before; he hadn’t been with a sexual partner in ages, and you stirred up feelings in him he didn’t even know he still had - feelings he shouldn’t be having, not toward someone who was so young, and especially not toward his student.

He had tried to curb his infatuation, once, by resolving not to give in to his urges. It had lasted all of three days and culminated in something so disgraceful he didn’t even want to think about it.

(He had once masturbated in his office just moments after you left, your scent still lingering in the doorway. As he fucked desperately into his hand, he’d imagined you kneeling secretively beneath his desk, supple lips around his cock. It’s still one of his favorite fantasies.)

He should be ashamed to call himself your professor, and yet...and yet…

A knock sounded at his door. “Dr. de Kuiper?”

Speak of the devil, and he shall appear. He jolted out of his thoughts, casting a glance at his desk where unfinished diagrams and unsolved equations sat. How long had he spaced out for…?

Siebren swiveled in his chair and found you standing in the doorway, hands clasped in front of you. His eyes were immediately drawn to your attire - blazer unbuttoned over a white dress shirt, cute pleated skirt dancing just above your mid-thigh, black thigh-highs accentuating your long legs…

You looked like a goddamn schoolgirl. That should not turn him on.

Even as he struggled to keep his eyes at an appropriate level, he couldn’t keep the genuine warmth and joy from his voice as he greeted you. “Oh, welcome! You’re not having trouble with the problem set, I hope?” He slid his glasses off his face and set them safely on his desk, prepared to have a nice chat with you.

“Ah, no, not really.” You stepped into his office, surreptitiously locking the door behind yourself. “I just wanted to see how your research was coming along, if that’s okay?”

“Of course, of course!” You’re always welcome, sat unsaid on his tongue. He gestured you over to his desk where he pulled out a holo-pad. As he drew up the latest 3D model, he felt your warmth settle into his side, your leg pressing against his own. He tried not to think about it.

“This is still a work in progress, but I think I’m getting closer to a vessel that can act as an appropriate harness.” The hologram flickered to life and showed a geometric model in the center, equations that you couldn’t even hope to understand running below. 

“Ohhh,” you breathed out. You leaned closer to get a better look at the diagram, stepping a leg in between his so that you practically hovered over his lap. “This is neat!”

Siebren willed his heartbeat to slow down. You were so close. “Y-yes, well, like I said it’s unfinished. This is only a prototype.”

“Still.” You flicked the hologram, causing the model to spin as you investigated it. “It’s really cool what you’re trying to do. I mean, control gravity?” You glanced back at him, a smile playing on your lips. “It’s hard to believe that it’s possible.”

He felt his chest swell with pride at your words. “It is. The theorems prove that much. Now, it is simply a matter of finding a practical implementation. If we take a look at the equations…” He pushed himself away from the desk with the intention of grabbing said equations, but his foot got caught around yours and pulled you back with him. You ended up falling right into his lap with a sharp yelp, his arms wrapped around your waist to keep you steady.

Well. This was turning out to be more like the plot of a bad porno, and Siebren hated himself for being able to name at least three that started out this exact same way.

The way you were sitting meant you were straddling his thigh. Which...okay, it wouldn’t have been good under any circumstances, but it was particularly awful now because he could feel your heat through your thin underwear. 

He tried to find words to make the situation okay, yet his mouth felt dry, his throat tight. Your face - as red as his felt - was mere inches away from his own. You fit against him like a puzzle piece, like this was meant to be.

“Please,” he whispered, not sure if he meant to ask for forgiveness or for permission, but any and all thoughts halted on the spot when he felt your lips press awkwardly against the side of his mouth.

God. You were so cute.

His immaculately-pressed self control snapped, and he raised his hands to cup your face and kiss you properly. You sighed into the kiss, open-mouthed, curling your hands into the soft fabric of his shirt. Your lipgloss tasted like cherries.

“We shouldn’t,” he mumbled against your lips. “You’re my student,” he insisted. “This is a-a gross...abuse of power, I can’t…” 

And yet, here he was, unable to pull himself from you for even a second. His hands slid up your shirt to rest against bare skin, and you shuddered against him as he moved to mouth at your neck. You tightened your grip on the armrests, willingly tilting your head to expose more of your soft skin for him. Siebren sucked with the intent of leaving marks, lightly scraping his teeth across a sensitive spot, and you moaned quietly in response - a sound he’d been imagining fondly for the whole semester.

Somewhere in the back of his mind, he registered your hips rolling slowly against his thigh in small, concise movements, like you were trying to be secretive about it. The image of you doing the same against his clothed erection made him choke on a moan, poorly hidden into your neck. You squirmed in his lap, fighting to shrug off your blazer, and in seconds his hands were atop your own.

“Let me,” he asked - no, begged -  and gingerly shooed your hands away. You fisted them in your skirt instead while he slowly undid the buttons of your shirt, sliding it off along with your blazer. They fell into a heap of fabric beside his chair. His eyes lingered on your skin, hand tentatively resting against the soft planes of your stomach.

“I-I, um -”

“Gorgeous,” he breathed, lovingly running his hands down your sides. “You are absolutely stunning.” He brought you in for another kiss, this one more passionate than the last, and slid one broad hand up your back. Deftly, he undid the clasp of your bra, and you gasped in surprise and moved to cover yourself.

“Wait, wait,” you begged, and he felt you pull away from him. Instantly, his hands settled onto your clothed hips. He felt guilt rise up into his throat at your expression - you couldn’t even meet his gaze, eyes flicking to the floor.

“Sorry, I’m sorry. I’m going to fast, aren’t I?” Horrible, horrible, he was absolutely 

disgusting -

Your hands settled on his, even as you turned your face away. “I just...why am I the only one getting undressed?” You looked up at him coyly through your lashes, and a relieved smile spread across his face. Okay. He could fix that.

“You’re nicer to look at than this old man,” he teased, and watched some tension evaporate from your shoulders. 

“It’s not fair.” Your hands moved from your breasts to his shirt collar, fingers twiddling the button there. “Please, professor?” you whispered, and god if that didn’t make his cock jump.

He breathed out slowly through his nose. “All right,” he conceded, and coaxed you off his lap so he could stand. Your eyes fell to his lap, no doubt looking at his straining erection. However, you suddenly moved to hide your face behind your hands.

“Oh no,” you whispered. “I’m so sorry, I-I didn’t mean…”

He glanced down, following your earlier line of sight, and found a nice little wet patch from where you had been sitting. “We’ve only been kissing,” he said, “and you’re already this wet?”

It came off a little meaner than he meant, but behind your hands he saw your flush extend up to your ears. 

Holy fuck.

Effortlessly, Siebren lifted you onto his desk, sending the contents clattering to the floor. You squeaked in surprise, momentarily latching onto him as your world spun - literally.  Even though you were sitting on his desk, he stood eye level with you. He leaned in for another kiss as he began undoing the buttons of his shirt. A moment later, he felt another pair of hands join his. 

“Let me,” you mumbled, looking shy but eager. “Please?”

He let his hands hang down by his sides as you worked his shirt open. He helped you pull it from his shoulders, and when his chest was fully exposed you flushed a pretty pink again.

“Wow,” you breathed, hands skimming over his toned abdomen, up to his deltoids, coming to rest against his biceps. “You’re...really hot.”

It was his turn to blush, but he took the praise in stride. “What, didn’t think your dusty old professor could be smart and strong?”

You bit your lip, shaking your head slightly. “I mean, I always kinda figured you were, ‘cause you have really toned forearms and sometimes when you roll up your sleeves I...never mind.” You ducked your chin into your chest in embarrassment, and Siebren pressed his forehead to yours. 

“No, no. Care to share with the class what you were saying?” He was trying to be playful, but instead you flushed hotter, a soft whine leaving your throat.

“You’re just super nice to look at all the time and I really…” Your voice dipped so low that it he had to strain to hear the last bit. “...really think you’re attractive as hell.”

Siebren couldn’t name the emotion that rose to the surface, so he instead leaned in and captured your lips in a kiss. At least this attraction wasn’t one-sided, and part of him hoped that you had been longing after him just as long as he had. “I’m glad,” he whispered against your lips. He wasn’t ready to confess that he’d imagined you naked more times than he could count, but just knowing that you thought of him like that helped curb some of his lingering feelings of guilt.

His hands settled at the hem of your skirt. “Up,” he commanded quietly, and you braced yourself on his desk, lifting your hips. He slid your skirt and underwear off in one smooth motion, leaving you bare and exposed for him - except for those damnable stockings.

Siebren stopped, stared down at the black fabric covering your legs. A bow sat neatly at the top of each one, tiny and white with black polka-dots. His fingers trembled at the band of your left stocking.

“Do you like them?” you asked, sounding hopeful. “I thought of you when I picked them out this morning.”

Oh god. Oh, Jesus. He was fucked. You wore them with him in mind? “Were you hoping for this?” he asked instead, thumbing the bow at the top. Your face flushed a shade darker, smiling sheepishly.

“I’ve been hoping for this for a while,” you admitted. Both Siebren’s cock and heart jolted at those words. 

God. He was so fucked. So, so fucked.

“You’re going to be the death of me,” he groaned. He couldn’t bring himself to take them off, not after knowing that. Instead, he slid down to his knees before you, your thighs framing his face.

“W-wait, professor, what are you doing?” 

He pressed a kiss to the inside of your thigh. “What I’m about to do is called cunnilingus; or, in layman’s terms, I’m going to eat you out.” He relished your whispered oh my god and drew you closer to him, hooking your thighs over his arms, his hands holding your hips. He pressed a quick kiss to the top of your mound and went to work, laving the flat of his tongue across your entrance. You jerked in surprise, thighs attempting to squeeze shut.

“Professor!” you gasped, squirming. He stilled you with those strong arms of his and sucked mercilessly at your clit, causing you to arch up. Your words remained stuck in his head. Professor. Your professor. He was vile, incorrigible, a perverted old man, and you tasted so sweet.

Siebren pulled away just long enough for him to slide a finger into your wet heat, amazed at how easily it went in, aided by your juices and his saliva. “Does it feel good?” he questioned. Sometime between then and now you had ended up on your back, draped across his desk. His tongue licked a wet stripe from his finger to your clit and you answered him with a low moan, a hand finding purchase in his short locks of hair.

Your hips rolled minutely against his mouth as he pumped his finger in and out of you, voice filling the air with a litany of pleas and incoherent mumbles. He slipped a second digit in you and felt you clench around him, voice climbing higher by the minute as he pushed you closer and closer to the edge. He stilled, instead placing a kiss to your inner thigh. “Be quiet, or we’ll have to stop,” he murmured. “The walls are rather thin.” Part of him almost wanted to be caught, consequences be damned. To have others know that he’s the one that has you so debauched, wound tight with need...the hicky was risky enough, he supposed, but he couldn’t help himself.

You wiggled your hips, drawing him from his thoughts. “I’ll be good,” you promised. “Please, professor?” 

He waited a beat just to make sure you hadn’t drawn any unwanted visitors, before he descended on you again. He fucked you with his fingers at a brutal pace, mouth latching over your sensitive nub, and he didn’t stop until you went stock-still, hips trembling as you came. Siebren pulled his fingers from you and cleaned up your juices, making the most obscene noises as he did so.

“Oh my god,” you mumbled. “Oh my god, oh my god. I can’t believe...holy fuck.” You supported yourself with your elbows, watching him rise and hover over you. He settled his hands on your hips, a smug little smile on his face.

“Feel good?”

“Yes,” you hissed. “Holy shit. That was...the best ever. Wow. Thank you.”

He leaned down to kiss you, slow and even, and his clothed erection pressed against you. After a second, you pulled away from him, hands finding purchase on his shoulders. “Um, but what about you?”

“Hm?”

You wrapped a leg around his hips, rutting against his bulge for emphasis. “You’re still hard.”

Siebren shook his head slightly. “Oh, no, no. I made you come, that’s enough for me.”

“But it’s not enough for me,” you said, almost pouting. “You’ve seen everything; it’s only fair that you let me see all of you, too.”

How could he compete with that logic? “You and fairness,” he said, but nonetheless stood straight and began to undo his belt buckle. You watched with rapt attention as he dropped his pants, letting them bunch around his ankles. His cock bobbed free from his briefs, long and thick and leaking, and your eyes widened.

“Oh my god,” you breathed out. Siebren wrapped a hand around his length and stroked it slowly, smearing precum. “I really - um, will that even...fit?”

He laughed quietly, grabbing your legs and lifting them over his shoulders so that your hips were raised slightly. “I’ll go slow,” he promised, “but we won’t do anything if you’re unsure.” He meant it to be comforting, but you shook your head wildly.

“No, no, please. I want this, I promise, please. I can take it.” Even so, you kept glancing at his cock, mouth pressed into a fine line. Your fingers tightened imperceptibly on the desk.

“Please don’t tell me I’m your first,” he said, putting two and two together.

You grew shy, suddenly unable to meet his gaze. “I-I mean, kinda? I’ve done some stuff, but I’ve never actually...y’know.”

His cock twitched and Siebren ran a hand over his face. “Oh, mijn God,” he breathed. You were a virgin. You were his star pupil, his favorite student,  and he was going to take your virginity. Him. Somewhere, he felt incredibly honored to know that you trusted him enough to let him be your first.

“Is...is that a problem?” You sounded so small and self-conscious that he felt something inside him break.

“No!” He was quick to reassure you, running a hand comfortingly down your side. “No, no, not at all, I just -” His voice softened. “Are you sure you want your first time to be with your physics professor? In his dingy office, no less?”

You curled your fingers around the hand at your hip, and Siebren was struck by the realization that your hands were so small, so tiny in comparison to his. “I’ve wanted you for so long, Professor, that I think if you don’t fuck me now I might actually die of desperation.”

That, at least, earned a laugh from him. Siebren placed a kiss to your calf and rubbed the head of his member against your slit, rubbing moisture onto his cock. “Ready?” he asked. 

“Please.”

Slowly, slowly, he pushed into you. He groaned almost instantly at the sensation, hands gripping the soft flesh of your hips. It had been too long. “You’re so tight,” he breathed out, resisting the urge to bottom out immediately. “Am I hurting you?”

You wrapped your fingers around one of his thumbs, heels digging into his shoulders. “No,” you said, though your voice drifted into a soft whine at the end. “It’s...it feels like you’re gonna split me in half,” you confessed. He slid another inch into you and you shamelessly moaned into the sensation, eyes fluttering closed. “I love it.”

After what felt like hours, Siebren sliding into you inch by torturous inch, he finally fit all of him inside your tight, wet heat. He had to stop and catch his breath, convince his body that he really didn’t need to come right away.

“How do you feel?” he asked. His hands went and rubbed along your stomach; if he pressed, he was sure he’d be able to feel the head of his cock bulging against your skin.

“Full,” you responded immediately. “But...it doesn’t feel bad. Feels good.” You twitched unconsciously around him, body adapting to the intrusion, and he cursed softly under his breath. “You can um...move, I think. Please.”

Siebren rested his hands on your hips again as he began to pull out. Going in the second time was a lot easier than the first as your juices slicked his cock, and soon with each thrust he was bringing his hips flush with yours. 

“Okay?” he asked you, sliding a hand up to your chest. “Tell - tell me if it hurts, okay?”

You covered his roaming hand with your own, holding tight to his fingers. “Good, it’s good, please don’t stop - oh, Professor, please…” You were whining now, head lolled back against the desk as Siebren set a relentless pace. He was reaching spots inside you that you didn’t even know you had, and one particularly rough thrust had you on the edge of a scream, arms flying akimbo over your head, knocking over a collection of pens.

“Shh, shh,” Siebren urged, clapping a hand over your mouth. His hips never stilled, desk rocking slightly underneath you. “People can hear you, they can - oh fuck -” Siebren stifled a moan into the soft fabric of your stockings, hot breath warming the skin underneath. “You’re so tight, so tight, goed god -” He pulled his hand from your mouth to instead paw at your chest, pinching one pert nipple between his fingertips.

“Pro-professor,” you begged, reaching for him. Siebren dropped your legs from his shoulders and pulled you into his chest, shifting you until you were sitting on the edge of the desk. You peppered sloppy kisses along his cheekbone, searching for his mouth, and he gladly gave it to you. The kiss was hot and messy, an aching mess of teeth and tongues that brought warmth to your chest and heat to your groin

“Professor, please, please, I’m g-gonna -” You cut yourself off with a needy keen, clutching at his shoulders, desperately rutting into him.

“Going to come?” he offered. He snaked a hand down between your bodies and began rubbing your clit. “Come for me then, baby. Come for your professor.”

He felt you clench around him, and quickly he closed his mouth around yours, swallowing all of your little sounds as you came. He pulled out and quickly jerked into his fist, muffling a groan as his cum splattered your stomach and upper thighs. For a moment, you both merely rested together, panting in the afterglow.

“Here,” Siebren finally murmured, unwrapping your limbs from around him. “Lay back, and I’ll get you cleaned up.” He grabbed a half-empty bottle of water and a few napkins, and wet them down slightly. Your eyes followed his every move. 

“How do you feel?” he asked as he began wiping away the...evidence of your activities.

“Sleepy...and satisfied…” You jolted a little as the cool napkin touched your skin, soothed a second later by Siebren’s large hand. “But mostly tired.”

“No pain?”

“A little,” you admitted. “But that’s normal, right?”

He stopped, peering at you. “Is it sharp, stinging pain?”

You shook your head. “No, it kinda feels more like...like a sore muscle. I think it’s just ‘cause you’re too big.”

Siebren smirked, running his thumbs along your hipbones. “You’re just not used to me yet.” Without waiting for your reaction, he pulled away and tugged his pants on, leaving his shirt crumpled on the floor. Instead, he grabbed your discarded clothing. “Here, I’ll help you get dressed.”

Somehow, having him pull your panties on, sliding one stockinged foot into them at a time, felt more intimate than him bottoming out inside you. He insisted on helping you with every piece, which made you flush in gratitude, and only once you were fully dressed did he grab his own shirt.

Searching for something to do, you cleaned up the mess you had made of the pens on his desk, a thought suddenly occurring to you.

“Hey, you, um, you know your favorite pen? The one you always kept in your breastpocket?”

Of course he knew what pen you were talking about. It was one he used to grade all his papers and sign important documents. The ink flowed well and it didn’t smudge or bleed through. It was an excellent pen, but he had lost it about a month ago and hadn’t been able to find it since.

“Yes, what about it?”

“Well, uh…” You turned your gaze away, fingers playing with the hem of your skirt. “I um. Stole it and used it as...to...y’know. So please don’t think that this is one-sided at all! Or that you’re taking advantage of me, or that I don’t want this...because I do. I really, really do.”

A soft smile crossed his features, and Siebren leaned in close to kiss you sweetly. “Thanks, sterretje. You put this old man’s mind at ease.” He paused, thoughts backpedalling. “Wait, you used my pen for what?”

You flushed a brilliant red and laughed nervously.

Well, at least he knows where it went.