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Dec 16, 2025

i wrote some professor x student sastiel smutty stuff, enjoy !!

sexy time below the cut

Sam knew what he was doing was wrong, he was twenty one years old, and the man he wanted was twelve years older than him. Sure, Cas wasn't a bad guy. In fact, he was possibly the most put-together, stable man Sam had ever met. The issue was that Castiel wasn't just some older guy he'd met at a bar, he was Sam's professor. If anybody found out, he could lose his place at Stanford, the thought of that alone was near crippling. He'd imagined how it would go; turning up on his father's doorstep, begging to be taken in again, maybe even apologising for ever leaving in the first place. He decided that he couldn't take the risk.

However, that didn't mean he had to abandon this little crush he had. He could still allow himself the simple pleasure watching the way Cas controlled a full lecture hall, he could stare at the man's lips as they form each word and imagine how they'd look saying 'I need you'. Sam would give anything to hear those words slip from Professor Novak's mouth. He thought about how it would feel to kiss him; whether it would be some slow and tender thing, like it was in the movies, or whether it would be messy, all teeth and tongue and sharing spit like they didn't need to come up for air.

Indulging in such fantasies had gotten Sam through most of the day, but now he had been caught — kind of. The lecture hall had somehow emptied out, with the exception of a handful of classmates still packing away their belongings, and Castiel Novak, who was leaning against his desk and staring directly at Sam.

"I trust that you have been paying attention, Mr Winchester?" He commented, his expression was difficult to read.

"Um…yes. Yes, Sir." Sam stuttered, already feeling flustered from the stern tone Professor Novak had used. How long has he been staring?

"Good, then you should be capable of telling me what I just said." Castiel looked at him expectantly.

Fuck.

He thought he had been paying attention, at least a little bit. Enough to be able to repeat the words back to his professor instead of admitting something along the lines of 'I was wondering how long I could stare at your lips before you realise not a single word has registered, and I've got a one-track mind hellbent on kissing you.' Sam looked at him with a blank stare, earning a frustrated sigh from Castiel.

"Mid-term participation reviews. Any students who have not scheduled a meeting should do so as soon as possible to have their file completed on time." Cas straightened some papers on his desk "You, Mr Winchester, are the only student who is yet to schedule with me."

Sam blinked, he wanted to give some sort of valid reason as to why he hadn't booked a time-slot. The truth was that he'd been avoiding this so that he wouldn't have to be alone with the man he was head over heels obsessed with, and make a fool of himself. He opened his mouth to respond, but was cut off immediately.

"Since I have had to remind you again, I suggest that you show up to my office at 6pm — if you want your student participation review to be worth anything."

Sam nodded in response and shuffled out of the hall, managing to squeak out a pathetic 'thank you, Sir' before disappearing into the crowd of students pushing their way in for their next class.

By the time 6pm came, Sam was a nervous wreck. He stood outside Professor Novak's office door for ten minutes, picking away at the skin on his fingers and fidgeting with the frayed sleeves of his jacket. He looked a mess, and he knew it, he just hoped he could hide it well enough to get through the meeting without embarrassing himself too much.

When he worked up the courage to walk into the office, he found Castiel sitting at his desk. He didn't look up, motioning with one hand for Sam to take a seat whilst he finished grading the paper he was working through.

"You're late." Novak spoke, not sparing Sam so much as a glance.

Sam cleared his throat as he sat down, it felt as if he couldn't breathe. "I'm sorry, Sir. The door was closed, I assumed you may have been busy with another student."

When Castiel finally looked up at him, with a tight jaw and sharp eyes, Sam felt exposed. It was as if Cas was staring into his soul. He had neatly placed his papers to the side of the desk, his full attention now focused on the boy in front of him.

"I hope you kept your schedule clear for this evening, Samuel. I believe this meeting may run over the allocated time."

"I-it's just Sam, Sir." he replied timidly "And yeah, my um, I didn't have anything planned tonight really. Just studying."

Cas let out a small hum of approval and nodded. "That's good, Sam." he said "Now for your participation review, I have noted that your attendance is near perfect."

"Thank you."

"I was not finished." Cas spoke sharply "Your attendance is near perfect, however, you do not seem to be present when you are in class. It's perplexing. Your grades are well above average, you've only missed two of my classes this semester, and yet when I look at you, it appears that your mind is somewhere else."

Sam could feel his face flush and he averted his gaze, eyes flitting nervously between random objects in the room, looking at anything but his professor.

"If there is something happening outside of your studies that's causing you problems, you can talk to me about it, or we can book you in for an appointment with the counsellor for wellbeing sessions." His voice was softer now, but only slightly "Do you want to tell me what's going on in your head?"

Oh God, this was going so much worse than Sam ever could have imagined. He couldn't tell Professor Novak the truth. Even if it didn't get him kicked out of the college, it would still make his lectures and seminars awkward. Maybe he would even have to transfer to a different course.

"No, Sir."

Castiel tilted his head, his eyes narrowing as he looked at Sam. "Forgive me if I am overstepping, you seem incredibly anxious."

"Well you're not exactly known for your welcoming demeanour." Sam said with a nervous chuckle.

To his surprise, Castiel actually laughed. It was soft, almost warm, and the exact opposite of whatever he had expected. He considered himself lucky, in this moment, to have been allowed to see through the cracks of his professor's stern persona.

"I get that a lot. I apologise if I made you uncomfortable, Samuel." He grinned, shaking his head slightly, before regaining his more professional temperament "If you don't want to tell me what's got you so distracted, could you at least let me know how to help you? You've got a bright mind, and I'd hate to see it go to waste."

"Uh, clearer instructions, I guess." Sam mumbled, staring at his hands "You're already pretty good with it, I just get a little distracted and when I can't catch back up it's like my brain shuts off and I get lost in my thoughts."

"Look at me, Sam."

His head tilted up without a second thought, meeting Castiel's gaze.

"Good." Cas said "Was that a clear enough instruction?"

His tone was right on the edge of being condescending, like he was both mocking and praising Sam at the same time. Sam only nodded in response, afraid that if he spoke he'd show just how much this was really affecting him.

"Use your words, Samuel."

"Yes, it was clear enough. Thank you." God, he sounded pathetic.

"Try again, don't forget your manners."

"Sorry, Sir." Sam's voice came out hoarse "Thank you, Sir."

Castiel nodded and made a small noise of approval. If this was his way of getting Sam to admit the thing that has had him so distracted in classes this semester, it was wildly unethical. And even worse than that, it was working. He stood up and took his jacket off, draping it over the back of his desk chair before sitting back down in front of Sam.

"Now, are you ready to tell me what's been going on with you? I've spoken with your other lecturers and none of them have noticed this attention issue of yours." He said casually.

When Sam didn't reply, Cas raised an eyebrow quizzically. For an agonizingly long minute, neither of them spoke. Sam shifted in his seat, all worked up and was almost ashamed of it. The silence stretched on, and the longer it continued, the more Castiel began to believe his suspicions were correct. Luckily for Sam, the infatuation went both ways, his professor was just better at hiding it.

"I would like you to lock the door please, Sam." His tone was calm and steady. Before the younger man could interrupt, he spoke again. "You may end the meeting now by leaving, if you wish. Or you can follow my very clear instructions and go lock the door. Your decision will not impact your participation report."

Sam stood, his legs trembling beneath him, and walked over to the office door. For a moment, he considered walking out. It would be the right thing to do, sure, but then what? Would he consider this whole meeting to have only been an odd interaction, maybe he could focus on the plausible deniability of it all. He'd return to his flat and fantasise about all of the different ways his evening could have gone had he just stayed?

Sam locked the door.

When he turned around, he noticed that Castiel had moved and was now standing in front of the desk, leaning back against it in an almost casual manner.

"Good boy, Samuel." He said, and Sam noticed that his voice was lower now; rough and practically dripping with something close enough to sin that it could be mistaken for salvation.

It felt like his brain had turned to mush. Sam was used to taking orders, his father practically raised him under military command, but this was different. He knew he could say no, and there wouldn't be any negative consequences. It made him want this, whatever it was, even more.

"What now, Sir?" He asked timidly.

Castiel grinned and tilted his head to the side with an almost mocking expression "So obedient, aren't you, Sam?"

Sam bit down on his bottom lip, fighting to hold back the pathetic whimper that was threatening to slip out. He nodded, maybe a little too eagerly, which earned a soft chuckle from his professor.

"Do you think this has been easy for me? Every day, I see your pretty face in my lecture hall, just staring at me with those puppy dog eyes. You may speak, Samuel."

Sam cleared his throat and took a shuddering breath in "I don't know, Sir." The admission of not knowing made him nervous all over again, like he had done something wrong.

"That's okay, Sam." Cas said softly, stepping closer "There's no wrong answers here, we're only talking. Yeah?"

Sam closed his eyes for a moment, really trying to take in those words. Eventually, he smiled slightly "Okay, Sir."

By now, Castiel was stood only inches away from Sam. He reached out slowly, making sure not to startle the poor boy, and gently cupped his jaw with his hand. He felt Sam flinch at the contact, and frowned slightly "You're safe, I promise. You don't have to do this, not if you don't want to."

The strange thing was that Sam did want this. He wanted it more than he could ever put into words. So he didn't, he showed Professor Novak just how much he wanted it, instead. He took a slow, deep breath and allowed himself to relax into the contact, leaning into Castiel's touch.

Cas began to caress soft circles against Sam's jaw. It all happened so slowly, so smoothly, that neither of them had realised his hand had moved until Cas' thumb was being traced over the boy's lips.

"Open." He said with a firm, yet gentle tone.

Sam obliged, parting his lips and looking at Castiel with glossy and hazy eyes.

"Good boy." Cas murmured as he slipped his thumb into Sam's mouth "Kneel."

Had Sam been focused on anything other than the pleasure he was receiving from the simple praise, he might have second guessed what he was doing. He sank to his knees, holding Professor Novak's gaze the entire time.

It was a smart move, making sure Sam's schedule was empty for the whole evening. Cas planned on taking his time with this, breaking his student apart just so he could be the one to put him back together again.

"That's it, Sammy" he praised him "Just like that, hold it."

His thumb slid over Sam's tongue and he let out a quiet groan as he slipped back out, tracing the outline of Sam's lips. He looked perfect like this; hazy eyes, messy hair and spit smeared lips parted beautifully. He whined beneath Cas, desperate to taste him again.

"You can either use your words, or be patient. The choice is yours, Sam." He said sternly as he watched the cogs in Sam's brain struggle to turn. When no response came, he figured his student had chosen patience.

He tapped two fingers to Sam's bottom lip and smiled slightly "Open up."

The second his lips wrapped around Cas' fingers, his eyes rolled back. Sam's mouth was soft. It was hot, and wet, and perfect. He didn't need to be told what to do here, and hollowed his cheeks, slowly sucking on the older man's fingers as if he'd craved this for his entire life.

"Such a good boy for me, aren't you, Sammy?" His voice was low, another groan slipping out as Sam kitten-licked at his fingertips "Does this feel good?"

Sam shifted on his knees, getting into a more comfortable position as he tilted his head back and looked up at his professor. Cas' fingers slid out of his mouth and rested on his lip.

"Yes, Sir. Feels so good." Sam whimpered.

For a moment, neither of them spoke. The silence that settled between their bodies was heavy, an all encompassing mixture of primal desire and hunger that threatened to suffocate them both if they did not break it soon.

"Sam, I would like you to kneel by my desk whilst I finish sending a few emails." Castiel said, already walking over to his desk. When he sat down and noticed Sam was yet to follow, he shook his head. "Samuel, that was a command. Kneel."

Sam nodded and crawled over to the space on the floor that his professor was pointing at, before kneeling in place and looking up at Cas curiously. Cas paid him very little attention as he typed away on his laptop, only occasionally reaching down to run his fingers through Sam's messy hair as a reminder that he was still conscious of his presence. By the time he had finished sending off documents and lecture plans, Sam was squirming impatiently by his feet and letting out small whines for attention.

With two fingers hooked under his jaw, Castiel used his grip to gently tilt the boy's head up. When his eyes met Sam's, he saw just how desperate he was. His gaze was unfocused, with flushed cheeks and his lower lip bitten raw.

"My poor boy," He mused "You look so pretty like this — so pliant. I could do anything to you, couldn't I? I could change you; train you to slip into this little headspace of yours whenever I please. Maybe I'll even give you a reward for your good behaviour, even if you're so blissed-out that you barely register that you've been following instructions."

Sam whimpered, his jaw going slack as he got drunk on his professor's words. If he could think straight, he would wonder about what Castiel would really do to him — if what he said had meant this could be more than a one time thing.

"Sam, sweetheart, I need you to use your words for me, okay? Do you want this?" He asked with a much softer tone this time.

Sam blinked as the words momentarily pulled him from his subspace "Yes, Sir. I Want this."

With Sam's confirmation, Castiel grinned. It was a wicked thing, he was in full control here and he knew it. Slowly, he threaded his fingers into Sam's hair and pulled him closer "Then beg." He whispered.

Sam took a slow, shaky breath and leaned upwards. His hand reached out hesitantly — afraid that somehow this was crossing a line, and cupped Castiel's jaw, pulling them closer to each other. They stayed there for a few seconds, so close that they were sharing the same oxygen, until Cas closed the space between them.

The kiss was searing; it started out slow, almost tender, before it became a mess. Teeth tugging at lips, sharing spit between them in a desperate attempt to somehow get even closer. Sam was pulled up so that he straddled Castiel's lap, the older man's hands threaded into his hair and tugging at it to get more access to flesh. His lips worked down from Sam's own, to his jaw, to his neck, to the sweet spot just above his collarbone. He left a trail of wet, open mouthed kisses and small bites that would bruise if Sam was lucky.

"This is so wrong." Castiel murmured as he came up for air, his breath ghosting over Sam's lips "Tell me to stop, Sam. Tell me to stop before we cross a line that we can't come back from."

Sam closed his eyes and rested his forehead against Cas' "We crossed that line when I walked through your door." He whispered "Please don't leave me like this, Sir. I don't know if I could take it."

Cas loosened his tie and ran his fingers through his hair, he was fighting a battle he knew he couldn't win. Temptation can be a cruel thing; he knew he shouldn't do this, he shouldn't see one of his students in this way. It was intimate in a way he never dared to let himself imagine, he'd spent many nights fucking his own hand to the thought of Sam sprawled out across his bed, whining and whimpering beneath him. Sometimes he caught himself whispering Sam's name under his breath when he finally pushed himself over the edge. He'd never imagined it to be like this, though, with Sam looking up at him through wide, innocent eyes. Every touch Sam gave was almost reverent, as if his professor was an idol to be worshipped. It is a fearful thing, to fall into the hands of a living god.

Castiel traced small circles against Sam's thigh as he spoke "I can't do this to you."

"You can, you have to. Please?" Sam begged, and rolled his hips against Cas', chasing any friction he could get "Please, a-ah fuck. Please, Sir?"

To pull away now would be torture, to let this go any further would be wrong. Oh well, he was already going to hell anyways.

"Alright. On your knees again, Sam."

The younger man obliged almost instantly, shuffling off of Castiel's lap and dropping to the floor with a soft thud. He settled into a comfortable position and rested his head on Cas' thigh, looking up at him through half-lidded eyes

"Can I?" he asked hesitantly.

Castiel swallowed and tilted his head back "Yeah."

He felt Sam's hands fumbling with his belt, clumsily pawing at him in a frantic effort to get him out of his suit pants as fast as he possibly could. After he finally unbuckled the belt, his wrists were held together tightly by one of his professor's hands.

"Use your teeth."

Sam's entire body went still for a split second as his brain tried to register what was happening. He leaned back down burying his face in Castiel's lap as he used his teeth and tongue to unbutton his pants. The metal zip felt cold against his lips.

"Oh come on, Sammy. You can work quicker than that, I thought you liked a good challenge?" Cas' voice was thick with want, and practically dripping with desire. Sam finally pulled the zip down with his teeth.

As a reward, Cas released his grip on the boy's wrists. Within seconds, Sam's fingers brushed against his hipbones, and slid his pants down. He wasn't sure how far he was allowed to go; if he had to wait for permission to touch, if he was allowed to remove the final layer between them. What Sam really craved was to taste Professor Novak. He wanted to savour this, to make sure he could remember the way it felt against his tongue, just in case he wouldn't get another chance to do it again.

"It's okay, Sam." Castiel said softly, his fingertips gently brushing over his jaw "It's just us here, you don't have to be nervous."

That was all it took for Sam to abandon all of the 'what ifs' running through his mind. He ducked his head down, his lips and tongue tracing the outline of Cas' cock through his boxers, and leaving a trail of dark, wet patches across the fabric. Sam hooked two fingers under the waistband and pulled it down at a tantalisingly slow pace.

"C'mon sweetheart, you caused this little issue. It's your job to fix it, unless-" Castiel's voice was cut off with a low groan as Sam took his length into his mouth — warm, and soft, and sinful. He couldn't help but moan again when he looked down and was met with the sight of Sam, who appeared so blissfully content; staring up at him all teary eyed, with his mouth full and cheeks hollowed.

He shifted his position slightly so that he could reach down and grip Sam's hair, pulling his head back just enough to get a good view of his throat. He watched the way it moved, bulging slightly each time he pushed his hips up, and listening to the soft, wet noises of skin against skin. With his free hand, he wrapped his fingers around the boy's neck, pressing his palm flat against the skin just below his chin to feel himself slide in and out of Sam's throat. It earned him the prettiest noise he'd ever heard; a lewd whine, almost pornographic in the way it slipped from Sam's lips and vibrated against the length of his cock.

Seeing Sam in this way could've brought him to the edge of release; his A grade, introverted student, kneeling before him and shamelessly moaning as he swallowed him deeper and deeper every time his head bobbed up and back down again.

"Sam, up now." Cas tapped Sam's hollowed-out cheek with two fingers.

Sam slowly pulled off, his tongue dragging across the tip as it was released from his lips with a soft pop. He let out a sob at the loss of contact, all worked up and frustrated.

"Mr Novak… what are you doing?" He asked quietly with his head tilted to the side.

"It's, um, fuck.." Cas had never come across as a nervous man, but for the first time, he actually looked unsure of himself "My name is Castiel, I want to hear you say my name."

Sam nodded slowly "Castiel." He whispered his name as if it were a prayer, something holy that could give him salvation.

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