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Deciding to live in the packhouse was a mistake. Although it offered protection and free food, room, and board there was no privacy. Nobody knocks, just dismissing anyone who got angry with an airy 'family' and the supernatural hearing makes it impossible to hide anything. Which was why it was so unusual for Peter to have the house to himself.
He had been reading in the library, tuning out the sounds around him as always before he realized that he wasn't hearing any heartbeats. The house was completely silent. It took a couple of minutes for the blue-eyed beta to understand what that meant but, after digesting, he powerwalked to his room. He quickly grabbed the box in the back of his closet, his large collection of sex toys making him hard without even trying. He picked his favorite dildo, a large purple one that knotted when you press the button on the remote.
Peter removed his clothes as fast as he could, putting away his other toys and grabbing the lube with supernatural speed before he crawled to the middle of his bed. He slicked his fingers up, leaving the dildo next to him, and started rubbing at his rim. He was tight after months of not having sex, the burn as he shoved an entire finger into himself in one go just making it that much better. The feeling of being filled made the wolf moan, his knowledge that nobody was around allowing him not to restrain his reactions. His walls were tight and damp with lube as he started thrusting, adding his middle finger before he was really ready and just reveling in the ache. The dildo was about 6 inches around and 7 long, girthier than Peter's own but shorter than the wolf's. Peter knew that he didn't have much time before someone came back to the house, his desperate need for release driving him as he put in his third finger.
It burned so badly that he had to stop for a moment, panting at the pleasure that barely overwhelmed the pain. He only waited until he could bear it before he was thrusting his fingers again. He started to use his hips, rocking into the hard thrusting of his fingers. He was just on the edge of coming, a couple more thrusts that dragged along his prostate would have been enough when he pulled his fingers out. The werewolf almost screamed in his desperation as the knot in his stomach clenched punishingly at the denied pleasure.
He had just barely come down from the self edging when he slammed the dildo into himself, the girth making him close his legs and clench tight until the intense burning stopped. When Peter finally was able to let himself go lax he was panting, the full feeling making him rock his hips even though it didn't do anything. The werewolf finally got himself mostly back together, moaning lightly when he held the dildo still and pushed his hips down. He continued the easy rocking until he couldn't anymore, his stomach so tight that he felt like he would fall apart if he didn't come in the next second.
Which was the second his nephew made himself known.
Derek let out a strangled moan from where he was standing in the doorway, his hands clenched tightly around the homework he was holding as he watched his uncle fuck himself on a dildo. The second he realized that he had made noise was also the second Peter stopped moving. The man on the bed froze for a second before the knot in his stomach got to be too much. He was panting harder than he ever had, his long cock almost purple where it was laying on his toned stomach as he tried to get his voice into some semblance of control. Listening closely he only heard one heartbeat, the rhythm telling the blue-eyed beta that his nephew was turned on.
"Either come here and fuck me or get out so I can finish, nephew." Peter drawled, his voice more unsteady than he normally would have liked but appreciated when the sound caused Derek to shift his hard-on in his jeans and the teen's eyes to dilate.
"Join?" The yellow-eyed beta repeated, his eyes roaming over Peter's sweaty body where he had started to rock on the dildo again.
"Yes, join. You and I both know that something has been happening between us, you can come over here and fuck me or you can leave."
Derek was out of his clothes and crawling onto the bed before the older man could even prompt him a third time. Once the teen got close enough Peter took the dildo out, flipped them so he was straddling his nephew, and kissed the teen before Derek could even gather his bearings.
The kiss wasn't nice, teeth and tounges and lips everywhere as the younger man's claws popped and dug into Peter's shoulders. The pain made the older man practically scream, the edging he had been doing, and the way his nephew felt under him making him even more desperate.
"Yes?" Peter double-checked.
"Yes," Derek confirmed, groaning and grabbing helplessly at Peter's hips as the man took him in completely in one swift movement.
The blue-eyes beta shouted out his pain before it turned to pleasure, his nephew's long cock having filled him so completely that it hit every sensitive spot inside him.
"Yes?" Derek asked first this time, his strong hips tense and shaking as he held back the overwhelming urge to thrust and keep thrusting.
"Mhhm" Peter mumbled, his frantic need and the amazing length filling him already making him lose his mind a little bit.
The older beta felt like he would explode if he so much as breathed, his nephew was so much bigger than the dildo he had been using it was a physical ache to take his cock. The younger man turned them back over carefully, pinning Peter's hands to the bed as he started moving. He kissed and bit along Peter's throat for a long moment, awed at the trust his uncle was showing by allowing another wolf that close to his throat. His thrusts started short, barely pulling out before shoving back in hard. The more noise his uncle made the faster he thrust, the older man's genius mind only took moments to understand the correlation, letting his voice go completely.
"Please....Harder...More!" Peter's words were slurred as he shouted out words between breaths.
With how hard Derek was thrusting every push of his hips made Peter grunt, the way the cock inside him slid along his walls knocking the air out of him and doing it again and again until before long the older man could barely breathe at all over the pleasure. The push and pull along his rim made him ache, feeling empty every time Derek pulled out. Peter was completely gone, garbled words falling from his mouth with no filter as his claws made Derek's back bleed and his eyes flashed. His nephew's claws had also popped, digging into Peter's hips and never getting the chance to heal as the younger man used the hold to pull his uncle back into his brutal thrusts.
"Come," Derek commanded, Peter instantly coming with a loud shout of pleasure and surprise. He hadn't even realized that the way his walls were tightening and his stomach was clenching was in preparation for an oncoming orgasm.
When he came his entire body curled up tight, his hold on his change completely gone as he went completely beta shift, the previously lax hole Derek was thrusting into clamped down so hard that the younger man couldn't move, only able to ride it out as the walls he was sheathed in massaged his length. The clenching and releasing on his cock had Derek coming too, his knot popping almost instantly as the younger wolf tightened his hands on Peter's hips convulsively.
Peter's orgasm had already been letting up when his nephew came, the knot making him groan in discomfort at being stretched so much. It was only made worse by the claws inside his hips going deeper. He just laid still, trying his best not to clench as his body demanded and absently stroking Derek's thick black hair and back as he moaned his way through his pleasure. By the time Derek was just coming back to himself the knot was at its largest, the bulb of flesh making his entire hole ache in time with Derek's heartbeat as pain radiated down to his lower back.
Derek took a moment to put together the pieces, gasping in surprise realizing that he had knotted. It had only happened to him a handful of times before and he hadn't been expecting it. The younger man gently took his claws out of Peter's hips wincing at the blood on the sheets from the cuts and stroking his uncle's stomach as his knot filled him. The yellow-eyed beta could feel himself through his uncle's belly, momentarily distracted by the way it felt before he brought his hands underneath Peter's tailbone.
"Do you want me to pull it or just help you through it?" Derek asked, knowing by now that knotting wasn't the most comfortable thing in the world for the person on the bottom and knowing that some people didn't like that kind of pain taken away.
"Just help me through it?" Peter requested through gritted teeth, the extra dimension of his healing hips making the pain radiate farther.
Derek just nodded wordlessly, stroking his uncle's back until the man relaxed enough that he could safely flip them over. Peter called out as the knot tugged on his rim, tearing up at the pain as his nephew just wordlessly adjusted them so that Peter was laying across Derek's chest. The younger man pulled his knees up between Peter's so that his uncle was forced to straddle him, supporting where they were tied and taking the pressure away from Peter's back.
Peter just hummed in thanks when the knot stopped pulling, finally able to enjoy the pleasurably sore, achy way that his hole randomly clenched around his nephew's knot. Derek stroked his uncle's hair down to his back and over his butt, gently rubbing the man's rim where it was filled before started the circuit again. Peter just laid there resting, hoping that this would become a reoccurring thing.
From then on, whenever the house was empty, Derek could be found in Peter's room.
Not that anyone in the family ever found out the real reason why.