A man half-transformed finishes the job

Paul didn't know how much time had passed since he had started cowering in this corner of his home. He'd been having a great time hanging out with his sister and her girlfriend, then fucking that smoking hot demon girl that had barged in, and then getting ready to rut his gorgeous blonde sister. Until that...existence made itself known. He was sure he'd never felt such fear before and likely never would again. The only thing he had been able to think as he crouched trembling in that corner was how glad he was that his god wasn't there for him.

Now, he slowly straightened. That deity was long gone, leaving the house quiet and empty save for himself and his sister. His sister, Mindy. His sister, Mindy, that he had last seen bound to the wall and helpless. Helpless to keep him from mating her. He looked over to see her there just like he remembered, though there was something different. A tell-tale wet patch was on the crotch of her jeans, so big that he wouldn't have believed it could be a sign of her arousal if he couldn't smell it. But he could and it was. Jealousy flared inside him at the thought of someone else having such control over her and his transformation, halted by his utter fear of the god, started again.

Paul's muscles bulged and thickened as he stalked towards Mindy, slumped and **** in her bonds. Dark fur grew over every inch of him, thick and black, while his face became the bestial snout of a wolf. Massive teeth extended out and dripped with feral saliva to match his transforming senses. With his swiveling ears, he could hear Mindy's light breaths and his hyper sensitive nose captured her delicious scent. If he hadn't been dead set on knotting her already, that delicious scent of unmated pussy would have pushed him to. As it was, it only encouraged him to rip her bonds and clothes apart with massive, clawed paws and pull her to him, his huge cock already extended from it sheath and ready.

Paul, finally a fully transformed werewolf, had no issue lifting his sister's body, resting her back over his knee to make sure he could penetrate her properly. The fact that she was his sister was absolutely irrelevant before his primal instinct to mate and knot a fertile woman. He even got just a little bit harder at the thought that he was about to defile his younger sibling with his potent wolf seed. He wondered if she would change like him or if she would forever be a woman taken and bred by a beast. Eager to find out he lined his cock up and thrust inside, hunching over so he could slobber over her big tits at the same time.

Paul quickly found the most effective way to fuck Mindy was by moving her body as opposed to his, and so he gripped her tighter in his claws and began jacking himself off with her limp form. He was her mate, he asserted, and she had to please him no matter what. Whether she was conscious of it or not. He was almost regretting that he wouldn't get to hear her cries as he bred her, only for her to suddenly wake up thrashing in his arms. His old self would try to comfort her and calm her down, he thought. His new, feral mind only cared about knotting her and her comfort was definitely not necessary for that. Using his overwhelming strength to largely keep her in check, he just kept pounding her down on his canine shaft, idly listening to Mindy's pleading voice.

"Paul, stop, this is wrong! You don't n-NNGGH need to do thissss! Please....please, big brother, stOOOPPP!" The blonde woman continued to wail through Paul's unrelenting thrusts, her begging for him to stop not making sense. Didn't she know he had to knot someone? It wasn't like he had really chosen her either, she was just the closest one when the instinct hit him. She was his bitch now though and he had to make her understand. She had to get knotted properly and having her constantly fighting back wasn't going to help. Knowing the perfect way to show Mindy her new place, he held back his mating urge for just a moment and pulled her off him.

Mindy's first impression as she was dropped by her werewolf brother was how much everything hurt. Her arms and legs ached from being stretched out and bound against the wall for so long, her back and neck hurt from being bent backwards over Paul's knee, her tits hurt from his slobbering licking, and her abdomen was the worst, aching and pulsing from the relentless pounding she had taken in her formerly tight pussy. She couldn't imagine her body ever recovering from the massive dog cock that had been **** into her barely used cunt. That was behind her though, she thought as she gently pushed herself up on her hands and knees. Something she had said between agonizing thrusts had gotten through to him, had made him drop her. She briefly thanked any and every god that could be watching while trying to summon the strength to stand up.

A heavy paw settling on her hip put an abrupt end to her silent litany of thanks. A thrill of terror rushed down her spine and right to her pussy as the other paw grabbed her other hip and held her firmly in place. She could feel her mutated brother's hot breath against her neck, his massive, furred body looming over her. "Stay....breed...bitch..." he growled in between panting breaths and Mindy whimpered with fear. As Paul's massive wolf phallus pressed forward and into her hole, the poor blonde crumpled and, unable to get away physically, sheltered herself in her mind. Ignoring the rapidly rising pace at which she was penetrated like a beast, she hid herself away in a corner of her psyche and let her body be.

With her conscious mind safely tucked away from her own bestial ****, her id and body took control, and they knew exactly what they wanted. Moaning out loud, the instinctual part of Mindy's mind reveled in the sex. Thrusting her ass up and back for better penetration, she let her tongue hang out of her mouth, aware of its increasing length and not really caring. She felt her body changing, legs twisting and coccyx extending while her curves gained size. Claws spouted from her fingers and toes, short blonde hair accompanying them and rapidly covering her body. Her long curls became a short mane extending down her neck and ears on top of her head twitched and laid down as she panted with pleasure.

The thick tail growing from the base of her spine, the morphing of her face into something canine and animalistic, the latent power in her thick thighs and big ass, the increasing weight on her chest: nothing mattered as much as her mate's thick, plunging shaft in her breeding hole. She was being bred. She was going to be filled with pups for her mate. She would give him as many strong heirs as he wanted and would let him breed her over and over and over again. That primal drive filled her up, pushed everything else away, and with the fearful remains of her human mind safely shut away, her animal took control and she yipped pleadingly to her mate.

When Paul had tried to tell Mindy what he needed, only for his words to come out half-snarled between growls, he had worried she wouldn't understand. He thought she would continue to cower and scream and beg him to stop. He had been relieved when, instead, she had begun to change, until she was a perfect mate for him: submissive and beautiful, with wide hips for breeding and birthing, and heavy breasts for nursing young. His young. He engorged even further at the idea of her trim belly swollen with his seed and pressed into her proffered ass even more. Looming over her, he possessively licked her snout, reveling in his ability to do so just because he wanted to. Mindy's tiny cry of satisfaction, full of pleading and obedience, was the final straw.

Howling with everything he had, Paul, forcing every bit of his cock into her cunt and smashing it against her womb, exploded in climax, his heavy testicles emptying themselves into his mate. Both werewolves could instantly feel Paul's knot expanding, tying the two together and ensuring not a drop of seed was wasted. The only place it had to go was in, and Mindy's fertile bitch womb was flooded with semen. The primal satisfaction of knowing his mate was being impregnated was enough to make Paul cum again, furthering the process.

The two wolves stayed there, in the living room of Paul's house, their humanity as abandoned as their clothes on the floor. Both were utterly satisfied, if only for a moment. Mindy was already thinking of how best to create a den to shelter their young, as well as how to give her mate a blowjob with her new mouth, though only once she was sure she was pregnant. Paul was considering how to ensure his mate's safety with demons and who knew what else was running around. He also wondered how long he could continue to fuck Mindy before he would risk harming his pups inside her. The thought of being unable to shoot his seed inside his bitch was a daunting and unpleasant notion, at least until he realized he was thinking too small.

Why have only one bitch? Why should only one womb swell with his seed? He could take as many bitches as he wanted. They would all bear his pups. He could breed all of them into his own fertile pack of canine women, eager, begging, and whimpering for his attention and his cock. Encouraged and utterly aroused by the idea, Paul set his huge paws back on Mindy's hips, looking forward to seeing them sway as she walked. First though, he wanted to fuck her again. Not breed her, that had already been ensured. He just wanted an outlet for this overwhelming fount of feral lust and Mindy wasn't going to complain. As he relentlessly pounded her into the floor, Paul imagined doing the same to countless more women, forcing them all down until they submitted to him and spread their legs. They'd spend their days servicing him with their wombs and their bodies, supple and yielding before his desires.