Playing with Fire Kit and his sister had gone into the woods together, both of them having changed into their non-anthro forms as the warm October sunlight shined down on the brillantly colored leaves of the trees above while they were slowly falling from above in preparation of winter. Today was Kit's birthday, and one of the things he wanted to do on his birthday was to go out in the woods with Firecat and mate with her while they were both in their non-anthro forms. Naturally, Firecat was more than willing to let her brother mate with her, but she was feeling a bit more playful as well. She ran into the woods out ahead of her brother as he followed behind, watching Firecat's swollen feral vixen vulva as she playfully coaxed him by flicking her tail from side-to-side whenever she stopped, much in the way any other feral vixen would do. Each time that she stopped, she'd let him get a little bit closer before taking off again, making him follow her whereever she went. Though she wanted him on top of her, Firecat wanted her brother to catch her before she'd let him mount her this time. Again, trying to act like just about any other horny feral vixen. She did make sure not to get too far out ahead of him though, helping to keep him motivated on the goal of mounting her without him giving up because of exhaustion. Not that this mattered to Kit as he had one thing on his mind, to make love to Firecat while they were in non-anthro form. His desires were made perfectly clear by the fully unsheathed fox cock of his as it remained exposed while he chased after his sister, periodically dripping precum from the tip of it as it landed on the fallen leaves at the forest floor. The two of them kept playing this game for a few minutes until Firecat reached the edge of a small creek that ran through the woods, stopping in her tracks as she could hear the approach of her brother. It was at this time she decided that she had teased him enough and got into the typical foxy-style position as she waited for Kit to catch her and mount her. Right behind his sister, Kit saw his sister's raised rump and tail off to the side while her purple vixen vulva twitched with excitement and knew that she was ready to let him mate with her. With a burst of speed, he quickly caught up to Firecat, mounting her the instant he got close enough to her as his front paws latched around her rear legs, ensuring that there would be no escaping this time...not that she'd want to anyway. As soon as he was on top of Firecat, the eager tip of his fox cock met the opening of her vixen vulva as Kit stayed in that position for several moments, panting excitedly while his tail rapidly moved from side-to-side as he clearly felt happy and was looking forward to mating with his sister yet again. Just as Kit was about to insert the tip of his shaft into his sister's vulva, both of the siblings heard the voice of a female giggle briefly. "Well...aren't you two a cute couple now?", the voice called out sweetly as hearing the voice made Kit immediately blush over being seen about to mate with Firecat as he dismounted her, turning around to find the source of the voice. The voice came from a female ninetales, one that was capable of speaking in English and possessed many other supernatural abilities. She had originally been resting on a rock next to the creek underneath a tree when the sounds of the two siblings got her attention. "Come on now, there's no need to be shy about it...my brother and I used to be just like you. In fact, sometimes when I think about it I can still feel how his knot felt inside me as we would be stuck together, sharing his love with me as he made my insides feel warm and tingly from his seed", she added as both Kit and Firecat sat there with their heads tilted in typical fox fashion as both of them wondered how exactly she knew that they were siblings...among other things. "Anyway, seeing the two of you together gives me an idea. I may not have my brother around to mate with me anymore, but I can help the two of you out with your own relationship", she commented as her red ninetales eyes briefly flashed golden yellow as a white aura surrounded her body as she stood up on all fours. Kit and Firecat simply just sat there, unsure what to make of it as they still seemed a bit confused. Then, without warning, the ninetales opened her mouth and unleashed a bright white flame that encircled the two siblings as they sat there. Seeing the fire around them, both Kit and Firecat felt very nervous as they moved in close to one another...fearing for their safety. However, the ninetales fem knew what she was doing and could sense their fear. "Relax, I'm not going to hurt the two of you...let the flames encompass you, they will not harm you", she coaxed softly as the two siblings had little choice but to trust her words and hope for the best. The fire circle slowly closed in around Kit and Firecat until it hit each of their bodies. When it did however, the two of them felt something strange, but also wonderful. Naturally, the flames were warm, but it wasn't a searing heat that would burn flesh or fur. Instead it was a gentle warmth that worked throughout their bodies as the magic of the female ninetales was working on them. On one of their front paws, a bracelet formed on each of them, each containing an amber stone with a red flame inscribed within it. However, things were only beginning to change. As they both felt the warmth of the flame, their bodies also changed with it. Their bodies retained their natural fur color and hair color, but their hair on the top of their heads began to take on a typical vulpix style. Furthermore, their single tails each split, forming into six curly tails that took on the same color as their hair. Then, the white flames that surrounded them faded away, revealing the two siblings as they now had been changed into a male and female vulpix, complete with typical vulpix capabilities (I.E.: able to breathe fire, etc). Their bodies now felt hot on the inside, but in their form it was an enjoyable warmth that made their bodies tingle a bit as the effects of the change were still taking shape. When the fire was out and the transformation was complete, the two of them discovered that the ninetales had disappeared while the transformation occured. This caught their attention for a moment, but was quickly ignored when Firecat looked over to her brother in vulpix form and rubbed her nuzzle against his. When she did that, Kit's focus returned to his sister as his foxhood began to re-emerge from its sheath, having gone back in while the ninetales female was around. It was clear that they still wanted to mate and the feeling of Firecat licking and nuzzling against him helped to stimulate Kit even further as he began to nuzzle her back. His shaft quickly came back out, growing to its full length in a matter of moments as drips of hot precum were now leaking from it, hitting the leaves on the ground and causing them to burn a bit from the increased temperature. Furthermore, the sweet scent that came from her six tails further added to his fire, making his shaft throb and turn a deep red. As she was nuzzling up against Kit, Firecat happened to look down and see that his member was erect and throbbing for attention as she once again felt her vixen folds quivering on the inside. Because they hadn't mated yet, she was still horny and from the sight of his cock, Firecat believed that Kit wanted to mount her once more...this time finishing what they had started before. With this in mind, Firecat moved away from her brother a little and got in front of him, bending over a bit as she kept her tails raised high as she showed off her swollen vixen vulva to him. This was all the motivation Kit would need to get up from his seated position and walk towards Firecat as his erection once again was evident with precum dripping onto the leaves on the ground, leaving scorch marks on them as it did so. The scent from her six tails kept his interest, further inviting Kit closer to her warmth as Firecat awaited him to climb on top of her again as she peeked back towards him. Finally, when he was close enough that she could feel the warmth of his breath up against her vulva, her tails dropped backwards over her lower body just before she felt Kit climb over her again. He was quick to climb onto Firecat, his front legs going back to her hips as he grabbed onto them while bringing the eager tip of his shaft up against her swollen vixen vulva. This time there was no one around, and this time Kit and his sister were determined to keep it that way until they were done. Once he was in a comfortable position, Kit aimed his tip at Firecat's opening, feeling it probe into her briefly right before he pushed forward, sending it into her canal as the two siblings were finally mating. Upon entry, Kit immediately began panting excitedly as he humped his sister at a decent pace, feeling his foxhood rubbing up against her vaginal canal while he held onto her tight. For the two of them there was a noticeable difference between mating before and mating now. For Kit, Firecat's vagina felt a lot hotter than it did before...undoubtedly a response to the transformation into a vulpix. For anyone else (or at least anyone who wasn't a vulpix or some other fire fox), it would burn them on contact. However, it felt just right for Kit. His body was able to feel Firecat's incredible internal heat while also not being able to be harmed by it. Of course, Kit wasn't the only one who felt a significant change. In her position, feeling Kit humping her from on top as he held onto her hips, Firecat was able to feel her brother's thick shaft moving rapidly and repeatedly through her. As it did so, it reacted the same way it normally would, pulsating with life as well as spitting out precum from his tip as it touched her cervix. However, everything felt much hotter for her as well. His precum was very hot and his shaft, while cooler than the precum also felt much warmer than it did before. Again, much like her brother, the increased temperature felt good to Firecat since her body was designed to take in the hot precum and shaft of a male vulpix. As a result, her walls tightened around Kit as she felt him move faster, increasing the rubbing between them as he moved, further stimulating his sex drive while the knot began to touch up against the outside of her vulva. As he continued to hump her, Kit began to move from side-to-side, much like any male fox would during mating as his shaft constantly moved through Firecat's hot vulpix vagina, the knot continuing to bump against the opening. He made sure to hold onto her tightly with his front legs as he was doing this, assuring that his maleness would remain inside Firecat at all times. In the meantime, Firecat also reacted as her walls began to contract inward around Kit's throbbing cock, increasing the rubbing between them as more precum was hitting deep inside her reproductive tract. By now, she was very hot and very moist inside, making for a very intense and happy feeling for Kit as his shaft constantly moved. Naturally, he wanted to knot and tie her and was working hard to get it inside Firecat as he remained on top of her, mating in true foxy-style. The knot kept bumping against Firecat's opening several more times before the moistness of her canal finally allowed it to pass inside her, quickly becoming surrounded by her intense fire vixen heat and tightness as she held onto it tightly. Kit kept moving from side-to-side during this time, feeling his knot beginning to grow into the warmth of his sister as the spurts of precum deep into her canal became stronger and more frequent. At this stage in their mating, both Kit and Firecat were panting constantly with smoke beginning to appear from each of their mouths as the final stages of the transformation were taking place. Each of them already had the internal fire going once they had changed into their current forms, but only now were they getting close to being able to shoot fire from their mouths. Kit's knot kept growing into Firecat's tightening folds as the knot moved from side-to-side with Kit, forming a strong bond between the two siblings as Kit felt the pressure in his balls growing rapidly. With his knot rapidly approaching it's full-size, it was only natural for him to want and fill his sister's reproductive tract with his sperm, much as he's done countless times before, acting on both his affection for her as well as natural desire. As his climax approached, small sparks of flame started to come out of his mouth, followed by the same from hers as the knot was nearly full-size and Kit could feel the pressure in his swollen testicles begging to be released. Then, as soon as they were firmly stuck together, Kit released his tensions. His sperm shot from the tip of his cock, splashing into Firecat's reproductive tract as much of his cream passed through her cervix as his mouth finally released a constant flame as he had his head tilted slightly upward (though even if he didn't the flame wouldn't affect Firecat since she was a vulpix as well). At the same time, Firecat felt the intense heat along with the tingle of her brother's cream hitting her insides and joined him in releasing her own flame. Their two flamethrowers met a short distance from where they were mating, combining their newly formed abilities as the flames began to circle around Kit and Firecat, creating a 500 foot high vortex of fire with Kit and Firecat in the eye of it. The vortex was carefully positioned inside the forest where it could not ignite any of the nearby trees since the purpose of this was to keep out anyone who got too curious during the next part of their mating. With the rapidly circulating and intense vortex of fire around them, keeping them in the middle of the calm eye, Kit could dismount Firecat as their mouths stopped shooting flame and complete the tie with her as his shaft continued to leisurely spurt more of his cum into his sister. The two of them were stuck together, unable to break apart from each other as their bodies reacted the way that they were meant to. However, the two of them wouldn't have it any other way as Firecat could feel her brother's hot seed filling up her womb slowly while Kit felt the tight grip of his sister's vaginal walls around him, holding his swollen knot in place while the vortex of fire continued to rapidly spin around them. As time progressed, the vortex of fire began to slowly diminish in size from the top downward as Kit and Firecat continued to remain tied in the middle. Although it was shrinking, it would remain around the two of them long enough for them to complete their tie, ensuring that no one would dare interrupt them at this most intimate time. A half-hour passed as Kit slowly emptied his balls into Firecat, placing a large amount of his cream into her hot vulpix folds. Then, once he had finished, their bodies began to relax with Firecat easing her grip on him while his knot began to shrink. The fire vortex around them was now only a few feet high and had slowed considerably from its peak, though it would still be strong enough to burn anyone or anything that got in too close to them. Then, at last, Kit's knot popped free of Firecat, followed quickly by the rest of his shaft as some of his leftover cream dripped out of her swollen vulva. With their tie now broken, Firecat rested on the ground, laying on her belly after being filled by Kit as the fire vortex was nearly out. Kit came over towards her and laid next to her, his nuzzle touching against hers just as the last bit of flame finally died out. The two of them were visible once more, with a ring of blackened ground surrounding them, having been scorched during the vortex, showing that if anything would've penetrated it that it would've been instantly incinerated. But now, Kit and Firecat could relax together, both of them feeling tired and happy after mating once again as both of them could feel the warmth of the afterglow. Eventually, Kit placed one of his front paws on top of Firecat as the two of them napped together where they were. Sometime later, when Kit and Firecat woke up, they were back to their normal selves as they got up off the ground and back up to their knees. Apparently, the transformation was only temporary and was controlled by the bracelets that appeared on their front paws, which had now turned into rings when they returned to normal. Even though they were back to their normal forms now, some things would remain with them regardless of what form they took. Though their vulpix forms were temporary, the effects of the transformation had some permanent effects. Both of them were now fireproof in regular fox form and their bodies would continue to remain hotter than they used to...though they'd still be the hottest in their vulpix form. This would make their mating more enjoyable in normal form as well, since the higher temperatures would be more stimulating for them. However, they wouldn't be able to find this out on their own until the next time they tried it.