Archive of Our Own ^beta

Stiles tightened his grip on Peter’s hips, his fingers digging in as he studied Peter’s face intently. His voice was low, a mix of concern and curiosity. “What’s going on? Did I mess something up?” He was trying to figure out why Peter had suddenly paused, his mind racing through possibilities. 

Peter’s grin spread across his face, wicked and unapologetic, the kind of smile that made it clear he was up to no good. “Someone’s here,” he said, his tone dripping with mischief. Without missing a beat, he started moving again, riding Stiles with the same reckless energy as before. “You didn’t do anything wrong, sweetheart, except for slowing down. Don’t stop now.”

Stiles’ eyes widened, and his heart skipped a beat. “Someone’s here? Who… wait, is it Derek? Is he back?” His voice was a little shaky, and he couldn’t help but ask because Peter was the kind of guy who didn’t give a damn who walked in on them. Peter would probably get off on the idea of someone watching, but Stiles wasn’t like that. He had boundaries, and those boundaries included his boyfriend Derek, his dad, and his best friend Scott. If any of them walked in on this, it would be a disaster. 

Sure, Stiles could try to play it off like this was some spur-of-the-moment thing, like it just happened in the heat of the moment, but that would be complete bullshit. He’d stopped lying to himself a long time ago. Peter was undeniably attractive—like, ridiculously so—and the thought of Derek, completely unaware, walking in and catching them in the act sent a jolt of adrenaline through him. It was wrong, but it also turned him on in a way he couldn’t ignore. The idea must have hit him harder than he expected because, without thinking, he thrust his hips upward with more force than Peter was ready for, catching him off guard. 

Peter let out a sharp gasp, his hands gripping Stiles’ shoulders for balance. “Easy there, sweetheart,” he teased, his voice a little breathless but still full of that same dark amusement. “Someone’s eager all of a sudden.” 

Stiles didn’t respond, his mind still racing. He knew he should stop, but the combination of Peter’s shamelessness and his own twisted thoughts kept him going, even as part of him screamed that this was a terrible idea. But when it came to Peter, terrible ideas always seemed to win out.

Stiles’ breath hitched as Peter’s words hit him like a punch to the gut. Peter’s voice was low, rough, and dripping with that damn Sex Voice™ of his—the one that always made Stiles’ skin prickle and his grip tighten involuntarily. His nails dug into Peter’s hips, leaving little half-moon marks in the soft skin as he tried to process what Peter was saying. 

“Who do you want it to be?” Peter asked again, his tone teasing and loaded with dark amusement. That wicked smile never left his lips, and his eyes gleamed with mischief, like he was enjoying every second of Stiles’ internal struggle. “Maybe Malia? My daughter?” he suggested, his voice dropping even lower, almost a growl. “Do you think she’d stop and watch? Maybe she’d even enjoy the show—seeing her ex-boyfriend, the guy she used to be with, fucking her own father. And not just that, but the uncle of the guy you’re *currently* dating. How messed up would that be, huh?”

Stiles felt his stomach twist, a mix of guilt, arousal, and something else he couldn’t quite name. Peter’s words were deliberate, designed to provoke him, to push buttons Stiles didn’t even know he had. The idea of Malia walking in on them—his ex-girlfriend, Peter’s daughter—was so wrong on so many levels, but Peter didn’t care. He thrived on the chaos, the taboo, the sheer audacity of it all. And Stiles hated how part of him couldn’t help but react to it, how his body betrayed him even as his mind screamed that this was all kinds of messed up.

“You’re such a bastard,” Stiles muttered, his voice shaky but trying to sound defiant. He glared up at Peter, but the effect was ruined by the way his hips involuntarily bucked upward, seeking more friction, more of that twisted pleasure Peter always seemed to drag out of him. 

Peter just chuckled, a dark, throaty sound that sent shivers down Stiles’ spine. “You love it, though,” he purred, leaning down so his lips were almost brushing Stiles’ ear. “Admit it. You love how wrong this is. How wrong *I* am. And you’re wondering, aren’t you? Wondering if she’d really stop and watch. If she’d see how good my big ass makes you feel, better than her pussy and wish it was her instead.”

Stiles clenched his teeth, trying to shut out Peter’s words, but they were already sinking in, already doing their damage. He hated how Peter could get inside his head like this, how he could twist things until Stiles didn’t know which way was up. But even as he hated it, he couldn’t stop himself from responding, from giving in to the heat and the tension and the sheer, undeniable pull of Peter’s depravity. 

“Shut up,” Stiles growled, his voice rough and uneven. But his hands stayed where they were, gripping Peter’s hips like he was afraid to let go, and his body kept moving, betraying him with every thrust. Because as much as he hated to admit it, Peter was right. He did love it. And that was the most messed-up part of all.

Stiles’ voice was tense, his words coming out in a rushed, almost panicked tone. “Whoever it is, they’re gonna show up any second now, babe. Just tell me—is it my dad or Derek? I need to know.” His mind was racing, trying to prepare himself for the worst-case scenario. The idea of his dad or Derek walking in on them was enough to make his stomach churn, even as his body refused to stop reacting to Peter’s movements.

Peter, on the other hand, looked completely unfazed. In fact, he seemed to be enjoying Stiles’ anxiety, his lips curling into a smirk as he wrinkled his nose in mock disgust. “Ew. No,” he said, dragging out the word like the very idea was beneath him. “Your dad? Really? Don’t get me wrong, Stiles, your father is a fine specimen of manhood—strong, capable, all that good stuff—but let’s be clear: I wouldn’t be riding you this hard and deep if I thought he was about to barge in here. That’s just not my style.”

He paused, his expression shifting to something even more mocking, his eyes glinting with amusement. “And Derek? Seriously? You think I’d be doing this if it was him? Please. I owe you a spanking just for suggesting it.” Peter’s tone was dripping with sarcasm, his words laced with that trademark arrogance that always made Stiles want to punch him and kiss him at the same time. “Do you actually think I’d be here, riding my nephew’s boyfriend’s big cock, if I thought Derek was about to walk in? Who do you think I am, Stiles? Some kind of twisted pervert man?”

Stiles glared up at him, his face flushed with a mix of embarrassment and frustration. “You’re such an asshole,” he muttered, but his hands stayed firmly on Peter’s hips, his body still moving in time with Peter’s rhythm. He hated how Peter could twist everything, how he could make even the most messed-up situations seem like some kind of game. But as much as he hated it, he couldn’t deny that Peter’s confidence—his complete lack of shame—was kind of a turn-on. And that just pissed him off even more.

Peter leaned down, his breath hot against Stiles’ ear as he spoke again, his voice low and teasing. “You love it, though. Admit it. You love how wrong this is. How wrong *I* am. And you’re still wondering, aren’t you? Wondering who’s about to walk through that door. Wondering if they’ll stop and watch. If they’ll see how good my body makes you feel and wish it was them instead.”

Stiles let out a low, breathy laugh, his fingers trailing over the marks he’d left on Peter’s hips. The indentations were still there, the skin not yet healed, and he could feel the slight ridges under his thumb as he rubbed back and forth, almost absently. His touch was possessive, like he was reminding Peter—and himself—who had put those marks there. “Then I don’t give a damn who it is,” he admitted, his voice rough but steady. He rolled his hips upward, meeting Peter’s movements with a deliberate thrust, making sure Peter felt every inch of him. “They can stay and watch me fucking your tight, huge, fat ass if they want. Or they can go wait in the bedroom until we’re done if they’re hoping for a turn with my cock. But I’m not stopping until your hole is stretched wide open and dripping with my come. Just like I promised you.”

Peter’s lips curled into a smirk, his eyes dark with amusement and something else—something that looked a lot like approval. He leaned in closer, his breath hot against Stiles’ mouth as he licked at his lips, teasing but not quite kissing him. “You always keep your promises,” he murmured, his voice low and dripping with that same smug satisfaction that always made Stiles want to both strangle him and fuck him harder. “It’s one of the few reasons I find your company tolerable.”

Stiles snorted, his hands tightening on Peter’s hips as he thrust up again, harder this time, just to watch Peter’s smirk falter for a split second. “You like my company because I’m your nephew’s boyfriend,” he shot back, his tone sharp but laced with a dark kind of humor. “You get off on deceiving Derek, on the fact that I’m his and yet here I am, fucking you just the way you like it. You’re a sick, twisted bastard, Peter, and we both know it. But I know exactly what you need. I know how to make you beg until your voice is hoarse and you’re desperate for it. That’s why your greedy, huge, delicious ass can’t get enough of my fat cock. Admit it.”

Peter’s smirk widened, but there was a flicker of something in his eyes—something that looked a lot like hunger. He didn’t deny it, though. He never did. Instead, he leaned in even closer, his lips brushing against Stiles’ ear as he whispered, “Maybe you’re right. But you’re the one who keeps coming back for more, Stiles. So what does that say about you?”

Stiles didn’t answer. He didn’t need to. His body did the talking for him, his hips snapping upward with a force that made Peter gasp, his fingers digging into the marks on Peter’s hips hard enough to leave bruises.

Stiles let out a sharp, breathy laugh, his voice low and rough as he muttered, “You know it, dickhead.” His words were cut off slightly when Peter clenched around him on purpose, that tight, deliberate squeeze making Stiles bite down hard on his lower lip to stifle a groan. He leaned in closer, his mouth brushing against Peter’s neck as he dragged his tongue over the skin, savoring the taste and the way Peter’s breath hitched in response. For what felt like the millionth time, Stiles wished he could leave marks that actually lasted—something to remind Peter who he belonged to, even if only for a little while. 

“Same way there’d be a line of people waiting for a chance at your ass,” Stiles continued, his voice dropping to a growl as he spoke directly into Peter’s ear. “You’d love that, wouldn’t you? Just a bunch of faceless dicks taking turns with you, one after another, not even caring who you are. Just using you, fucking you raw, and filling you up until you’re dripping with it. That’s what you want, isn’t it? To be nothing but a hole for anyone to use whenever they feel like it.”

Peter’s response was a low, throaty chuckle, but Stiles could feel the way his body reacted—the way he tightened around him again, the way his breath came a little faster. Peter didn’t deny it, and that was all the confirmation Stiles needed. He knew Peter too well, knew exactly what kind of twisted fantasies got him off. And as much as Stiles hated to admit it, the idea of Peter being used like that—of him being so completely out of control, so completely at someone else’s mercy—was kind of a turn-on. 

But Stiles wasn’t about to let Peter have the upper hand. Not this time. He thrust up harder, deeper, making sure Peter felt every inch of him as he growled, “Too bad you’re mine right now. And I’m not sharing.” His hands gripped Peter’s hips tighter, his nails digging into the skin as he set a punishing pace, determined to make Peter forget about anyone else but him. Because as much as Peter liked to pretend he didn’t care, Stiles knew the truth. Peter might be a sick, twisted bastard, but he was Stiles’ sick, twisted bastard. And Stiles wasn’t about to let him forget it.

“I knew you were a slut, old man,” Isaac said, his tone dripping with amusement as his gaze flicked from Peter to Stiles. “But seriously, Stiles? Peter? Your boyfriend’s uncle? You could’ve chosen me instead, you know.” He crossed his arms over his chest, his smirk widening as he openly stared at the two of them, not even trying to hide his interest.

Stiles froze for a split second, his body tensing as the voice cut through the room. It wasn’t Peter’s voice—it was younger, sharper, and coming from the direction of the front door. Stiles turned his head, his eyes widening as he saw Isaac, Derek’s beta, leaning casually against the doorframe. Isaac had that same lazy, cocky grin on his face, his eyes locked on Peter’s ass as it bounced shamelessly on Stiles’ dick. The sight of Isaac standing there, watching them like it was some kind of show, sent a jolt of mixed emotions through Stiles—embarrassment, irritation, and, annoyingly, a flicker of arousal.

Peter, of course, didn’t miss a beat. He leaned forward slightly, his movements deliberate as he ground down on Stiles, making sure Isaac had a perfect view of everything. The head of his dick rubbed against Stiles’ abs, leaving a sticky, wet trail as he smirked at Isaac. “I’m totally aware of that,” Peter said, his voice smooth and teasing as he winked at Isaac. He was clearly enjoying the attention, playing it up for their unexpected audience like the shameless exhibitionist he was.

Stiles, on the other hand, was trying to process the situation. His face was flushed, a mix of embarrassment and frustration, but he couldn’t stop his body from reacting to the way Peter was moving on top of him. He glanced over at Isaac, his voice low and slightly strained as he whispered, “Are you going to tell him?”

Isaac raised an eyebrow, his grin turning even more mischievous. “Tell who? Derek?” He shrugged, his eyes still locked on the two of them. “Maybe. Maybe not. Depends on how this plays out.” He took a step closer, his gaze lingering on Peter’s ass as it continued to move in rhythm with Stiles’ thrusts. “You know, I always wondered what it would be like to join in on one of your little… sessions. Maybe this is my chance.”

Stiles groaned, partly in frustration and partly because Peter had chosen that exact moment to clench around him, making it impossible to think straight. “You’re both impossible,” he muttered, but he didn’t stop. He couldn’t. Not with Peter riding him like that, and not with Isaac standing there, watching them with that hungry look in his eyes.

Peter chuckled, his voice low and dripping with amusement as he leaned back slightly, giving Isaac an even better view. “Well, Stiles,” he purred, his tone teasing, “looks like you’ve got an audience. What are you going to do about it?

Isaac didn’t bother waiting for Stiles to respond. He just shrugged, his smirk never leaving his face, and said, “Don’t mind me for now. I’m just gonna sit over here and watch.” He closed the door behind him, making it clear he wasn’t planning to leave anytime soon. It was obvious Stiles and Peter weren’t going to stop, and Isaac wasn’t about to miss the show. Stiles could hear the sound of Isaac’s shoes as he walked across the room, the soft shuffle of fabric as he settled into a chair or couch—somewhere comfortable, somewhere with a good view. And Stiles could *feel* Isaac’s eyes on them, watching intently, taking in every detail of Peter’s movements and Stiles’ reactions.

Peter, of course, didn’t seem to care. If anything, he seemed to enjoy the added attention, his movements becoming even more deliberate, more exaggerated, as if he was putting on a performance just for Isaac. Stiles, on the other hand, was torn between irritation and arousal. He glanced over Peter’s shoulder, his eyes locking with Isaac’s for a moment before he flashed him a slow, sexy smile—the kind of smile he’d perfected back in college, when he’d finally started to grow into himself and realize the effect he could have on people. “You can touch yourself if it gets to be too much,” Stiles said, his voice low and teasing. “Permission given and all that.”

Isaac chuckled, his grin widening as he made himself even more comfortable. “Thanks, Stiles,” he replied, his tone casual, like this was just another Tuesday night for him. And honestly, it kind of was. This wasn’t the first time Isaac had watched Peter fucking someone else. Peter’s exhibitionist kink paired perfectly with Isaac’s voyeuristic tendencies, and they’d crossed paths like this before. The fact that Peter was so open about his desires—and so shameless about putting them on display—made Isaac a regular guest at these kinds of scenes. And who knows? Maybe he’d even join in later. That was always a possibility when Peter was involved.

Stiles could feel the tension in the room, the way the dynamic shifted with Isaac’s presence. It added a new layer of heat to the situation, even if Stiles wasn’t entirely sure how he felt about it. But he didn’t stop. He couldn’t. Not with Peter riding him like that, not with Isaac watching so intently, and definitely not with the way Peter’s body felt around him, tight and hot and perfect. So he kept going, his hands gripping Peter’s hips as he thrust up into him, determined to make the most of the situation—whether he liked it or not.

Peter’s voice cut through the room, sharp and impatient, as he glared down at Stiles. “If we’re done with the whole shit-chat thing, can you *please* focus on fucking me instead of playing nice with my idiot nephew’s beta?” His tone was dripping with irritation, and his eyes narrowed when Stiles actually slowed down, his movements turning teasing and deliberate, like he was trying to push Peter’s buttons. 

Stiles raised an eyebrow, a smirk playing on his lips as he glanced up at Peter. “At who?” he asked, his voice deliberately casual, like he didn’t already know exactly who Peter was talking about.

Peter’s jaw tightened, his frustration obvious. “My idiot nephew’s beta,” he repeated, his words clipped and annoyed.

Stiles didn’t respond right away. Instead, he kept his movements slow and lazy, rolling his hips in a way that was clearly designed to drive Peter crazy. He could see the way Peter’s top lip twitched, the way his body tensed with every slow, deliberate thrust. “I’ll only ask once more, Peter,” Stiles said, his tone light but with an edge of challenge. “Who are you talking about?”

“The idiot,” Peter snapped, his voice tight with frustration. He wasn’t in the mood for games, and Stiles knew it. But Stiles wasn’t about to let him off the hook that easily.

Instead of answering, Stiles just smiled, his eyes locked on Peter’s face as he continued to move at that infuriatingly slow pace. He could feel how hard he was, how ready he was to come, but he wasn’t about to let Peter know that. Not yet. He glanced over Peter’s shoulder, his gaze landing on Isaac, who was still sitting there, watching them with that same lazy, amused smirk. “Do you have a good view?” Stiles asked, his voice low and teasing.

Isaac didn’t miss a beat. “Uh huh,” he replied, his tone casual, like this was just another day for him. And honestly, it kind of was. Isaac liked to watch—that much was obvious—and Stiles knew he wasn’t going to say much else. Not until after. But Stiles wasn’t about to let him off that easily, either. He moved his hands from Peter’s hips, gripping the older man’s massive ass instead. He pulled the round, huge cheeks apart, giving Isaac a quick, unobstructed view of his thick, twelve-inch dick sliding in and out of Peter’s tight hole. 

Stiles leaned in closer, his lips brushing against Peter’s ear as he murmured, “Do you like that, babe? Like being stuffed full by my huge dick?” His voice was low and rough, his own version of the Sex Voice™, though he knew it wasn’t as good as Peter’s. It wasn’t perfected enough for a trademark—not yet, anyway. But he was working on it. And judging by the way Peter’s body reacted, he was getting closer.

Peter didn’t respond, but he didn’t need to. The way his body clenched around Stiles, the way his breath hitched, was answer enough. And Stiles wasn’t about to stop now. Not when he had Peter right where he wanted him.

“Damn, I should just shove my dick down your throat to shut you up for once,” he grumbled, his tone all pouty and sulky, like a kid who didn’t get his way. But Stiles? He just flashed that cocky grin of his, completely unfazed by Peter’s bitchy little comments and those half-assed threats he liked to mutter under his breath. They both knew the real deal—who was really calling the shots here. And let’s be real, there was a reason Peter was so damn eager to drop to his knees for Stiles, and it wasn’t just because Stiles was packing a huge cock. Nah, it was way more than that. Peter’s eyes locked onto Stiles’, and that wicked, sinful smile of his spread across his face. “You think I’m gonna cave that easy, sweetheart? Think again.”

Stiles just smirked, leaning in close, his breath hot against Peter’s lips. “Oh, keep being a stubborn little brat, baby. I’m into it.” Then he kissed him, hard and demanding, his tongue teasing Peter’s lips as he pulled back, leaving him wanting more. “We’ve got all night, babe. Ain’t that right, Isaac?”

“Absolutely,” Isaac breathed out, his voice shaky and rough as his hand moved faster over his cock. He couldn’t tear his eyes away from the scene in front of him—his alpha’s mate, Stiles, all tangled up with his alpha’s uncle, Peter. It wasn’t every day you got to see something this wild, this messed up, and Isaac wasn’t about to let the moment slip by. His heart was pounding, and his mind was racing, but one thing was clear: he wasn’t going to waste this opportunity. 

Quickly, he fumbled for his phone, his other hand still working himself as he hit record. This was the kind of shit you didn’t just forget—it was too damn hot, too twisted, and way too good not to save for later. Isaac knew he’d probably regret it later, but right now, all he could think about was how insane it was to see Stiles and Peter going at it like this behind Derek's back. the sheer audacity of it all had him completely hooked.

“Damn,” he muttered under his breath, his hips jerking slightly as he kept stroking himself. “This is some next-level fucked-up shit.” Isaac thought, But messed up or not, he wasn’t stopping. Not now, not when he had a front-row seat to something this rare, this dirty, and this unforgettable.