Tori woke to the sound of the front door opening, rolling over and burying herself in the duvet, unwilling to leave her post-workout nap so soon. She could hear muffled grunts coming from the hallway, heavy thuds as her girlfriend struggled with… something. Finally, the thuds stopped and the door closed, Tori smiling slightly as she settled back to sleep…

   “It’s here! It’s finally here!” came the cheerful voice of Amy, her insistent, tugging hands robbing any chance Tori had of returning to sleep.

   “What… what’s here?” Tori murmured as she rolled back over, dragging a loose strand of jet black hair out of her face. Blinking a few times, she found herself staring at the wide face of her girlfriend. Amy grinned back, her hazel eyes sparkling with excitement.

   “Your costume, silly!” Amy threw the duvet off Tori,  not giving her chance to protest, tugging at one of Tori’s muscular arm, “now wake up before I drag you out.”

   “Alright, alright, I’m coming,” Tori waved her girlfriend off, sliding slowly out of bed, dressed only in pyjama shorts and an old t-shirt. She knew Amy couldn’t really drag her away but there was something oddly endearing - and infectious - about Amy’s enthusiasm that Tori just couldn’t ignore. Amy sprinted off ahead of her, leaving Tori to pace along after her, muscles still sore from her exercise. Her mind wandered, struggling to think what costume Amy was talking about.

   Out in the hall, Amy was halfway through opening a cardboard box longer than she was tall, making Tori wonder just how the hell she managed to get it through the doorway – but what Amy lacked in stature she more than made up for in determination, reminding Tori just why she loved her. Amy could defeat anything.

   “Just what have you got me, anyway?” Tori asked, walking over to help prise the cardboard apart.

   “It’s your costume for Halloween! Can’t have you going to the party without a costume…”

   “Oh, really? Are you see that’s the only reason?” Tori had known Amy for long enough to tell when she was hiding something.

   Amy blushed beet red, tilting her head so her hair spilled down, hiding her face the way she always did when she was embarrassed. It kind of made Tori’s heart melt.

   “Well… that and I thought you’d look pretty sexy in it,” the smaller girl admitted after a moment. “You know, if you want?” Her tone was hesitant, but Tori knew she could never say no after that, pausing a moment before replying.

   “What are we waiting for, then?” She wedged both hands under the cardboard, lifting up quickly, the top of the box tearing away to reveal a sea of black packing foam inside. Tori paused a moment, the bigger question coming back to mind, “... just how large is this costume, anyway?”

   Amy didn’t reply, smirking a little as she pulled the top layer of foam away with a theatrical flourish, revealing the costume that lay within. Something like latex lay within, the fiery orange material blazing against the black foam of the box. Tori peered closer, her eyes following the tapered end that lay on top. It grew wider steadily, folded back and forth over itself, down into the depths of the box.

   “It’s… a tail?” Tori asked, mostly to herself, kneeling down beside the box and reaching in, gently lifting out the end of the tail. The costume had a strange satin softness to it Tori hadn’t been expecting, her hands running across the fine pattern of scales embossed into the material. Running it between her fingers, it had a pleasant thickness to it, and a surprising weight as she pulled more and more of the tail out of the box. It continued to unfold, revealing more of the speckled orange tail, growing steadily wider until it was a couple of feet across. Its colour shifted to a vibrant yellow on the underside, the texture of the scales changing to wide bands. She had to awkwardly shuffle to one side, letting the costume bundle up beside her, wondering just where it ended.

   Tori half-expected the tail to end in some large rump, massive thighs leading the the powerful claws of a dragon. Instead, the ending was more subtle and gradual, a soft swell into wide hips that she might have missed if it weren’t for the suddenly narrow waist. Tugging gently at the costume, more of it spilled out, the contours of a (definitely feminine) torso giving way to scaled arms: bulky, but not massive, the hands clawed but not far off a human’s. Tori’s heart beat faster in excitement and anticipation, hands reaching under the thick neck of the costume, feeling the rough texture of the foam under her fingers as she pulled the costume’s head into view.

   Her eyes gazed into the glassy eyes of a serpent, lenses of transparent green plastic set into the snake’s snout. It seemed huge, large enough to fit her own head in, and then pushing forward into a broad wedge. She turned it this way and that, watching the pattern of light dancing across its scales. The mouth flipped open, the wide jaw revealing the rich purple lining of the costume and the rows of short fangs lining its edge.

   “Wow…” she gasped, practically hypnotised by the sight of it, something like a naga but seeming infinitely sexier than anything Tori had imagined. Amy stood nearby, face lit with excitement and glee: half at the sight of the costume, half in delight of her girlfriend’s reaction.

   “You going to try it on?” Amy squeaked, impatient, barely holding back her excitement. Tori fine tore her attention away from the costume, looking over to see Amy swaying gently from foot to foot. Tori smirked, she always loved seeing Amy so excited.

   “Alright, alright… if it will stop you from exploding,” Tori replied, though the way the costume called to her she didn’t need a second reason to try it on. She stood, lofting the costume, the heavy material hanging loose in her hands. Dragging it backwards through the hall, the only part of their house long enough, she let the costume unfurl completely.

   A seam ran along the back, the slick surface of the costume holding itself sealed. Gently, Tori ran a finger through it, splitting it open to reveal the inside. Inside, the costume was the same purple material as the mouth, perfectly smooth and strangely inviting. Looking down into the tail, the material thickened, padding to hold her legs together inside the tail, though Tori still wondered how she was meant to move about.

   “So, I guess I just slide myself in…” Experimentally, Tori slid an arm into the costume. The slick inside of the costume glided effortlessly across her skin, hugging and squeezing her muscles, fingers pushing out into the costume’s claws, their hard shapes digging a little into Tori’s skin. From the other side, Amy could see Tori’s arm filling out the costume, the scaly material contoured perfectly to her muscles, building slight, making Amy’s heart beat faster.

   “Looking good, babe!” Amy cheered, eyes wide as Tori started to pull the torso of the costume over itself, the material awkwardly catching against the fabric of her t-shirt, sticking and crumpling.

   Tori muttered and grumbled in frustration, wondering if there was some trick she was missing, but no matter what she tried her t-shirt kept getting caught. Tori huffed, turning to look at Amy, glaring at her girlfriend’s griddy grin. “... I’ve got to get naked, haven’t it?” she sighed, her expression med by enthusiastic nods.

   Peeling her arm out of the costume, already missing the tight feeling of rubber around her arm, Tori gently laid it across the floor. Quickly stripping out of her clothes, she found herself glancing back at the costume, the promise of its warm material hugging her body as she stood naked in the cool of the hallway. Amy bit her lip, blushing red at the sight of her girlfriend, excitement and anticipation building again, imagining the fiery scales of the costume covering her chest, defining each and every muscle.

   “The things I do for love…” Tori sighed and picked the costume back up. Letting the upper part of the costume fall forward, she spread the base of the opening wide, staring down into the dark tail of the costume. She slipped one leg inside, feeling the thick padding of the tail brushing against her leg, leaving little room for the second. As her foot pushed deeper inside, not feeling any end to the lining of the tail, Tori was sorely tempted to grab Amy and stuff her inside, let her girlfriend have the ‘fun’ of being her tail. Maybe next time…

   For now, she pressed her foot flat against the lining, awkwardly balancing as she reached her other foot inside. The tail was much tighter, pressing her legs together, making her hop about awkwardly for balance. Settling her feet together, she tugged the costume up to her waist, feeling the material hug her hips, pressing against the thick flesh of her rear. She turned about, getting a good look at her ass, the gentle rise it made against the tube of the tail.

   Amy watched with eager anticipation, stepping carefully around the length of the tail, taking a good look at Tori struggling to pull the costume up her body. Gingerly, she reached out a hand, pressing against the side of Tori’s tail, the padding pressing into her thighs. Tori gasped, feeling strangely sensitive, as if she could feel each of Amy’s fingers pressing into her skin. Recovering, Tori smirked, playfully batting Amy’s hand away. “Hey! At least wait until I’ve put the whole thing on…”

   Amy huffed, pouting a little, stepping back to lean against the wall. If she wasn’t allowed to touch, she could at least have a front-row seat.

   Tori returned to the arms of costume, putting the front up over her, the costume gently brushing against her breasts. Biting her lip, a mostly successful attempt to suppress how good the lining felt against her body, Tori slipped one hand in after the other, tugging the costume tight around her fingers, surprised how little the costume restricted her movement. Running clawed hands up her arms, she could feel every bump and scale across the costume’s skin, making her shiver a little. Settling the costume over her shoulders, she reached back to pull it tight around her torso, fumbling as she started to press the opening of the costume closed.

   “Need a hand?” Amy offered, though she didn’t really want to miss the costume stretching over Tori’s muscular chest, the limp head obscuring the sight of Tori’s breasts filling out the costume. Tori’s hands ran across her front, following the chevron-bands of scales pointing down towards her pelvis, smoothing out any lingering creases and wrinkles. Inside, Tori could feel the lining sticking to her skin, seeming to find every contour of her chest. Outside, Amy watched with delight as Tori’s muscles showed through the material, rippling as she moved.

   Stretching her arms out ahead of her, Tori marvelled at how perfectly the costume fit her, wondering just how much the costume had cost Amy. (And did Amy measure her while she was asleep?). It felt like the costume was hugging her body, gently squeezing, an oddly reassuring tightness. Just wearing the costume made her feel powerful, undefeatable, and strangely sexy. Flexing each arm in term, the movements helped settle the costume about her torso, the slick opening slowly sealing itself up, running up Tori’s spine. Only the head remained.

   Breathing in and out slowly, scaled skin rising and falling, Tori looked down into the head of the costume. She could feel her heart beating rapidly in her chest, a sense of excitement – or was it apprehension? – growing as she pulled the serpent’s head over her own. The mask hugged the sides of her hair, flattening her hair and ears as she tugged it all the way on. The slick material pressed flat against the rest of the costume, the seam all-but invisible. Light streamed in through the eyes and open mouth, the snout sticking out ahead of her, forcing Tori to spin around to look at Amy.

   “So… how do I look?” Tori asked, the costume’s jaw clinging to her own as she spoke, awkwardly opening and closing. Amy’s stunned impression seemed to say it all, eyes wide in wonder.

   “You- it’s- you look- amazing!” Amy finally cried, leaping forward to hug Tori, disappearing from view. Tori felt the weight of her hitting her chest, almost knocking her backwards, Amy’s arms wrapping around her back… gently pressing the seal firmly closed before stepping away.

   “Careful!” Tori started to protest before the rush of heat washed over her, every muscle in her body tensing up. She tried to step backwards but her feet refused to move in the confines of the costume, sending her tipping over backwards and landing awkwardly on her rear. The costume felt tighter around her body, pressing into her skin, costume and human starting to blend into one.

   Breathing heavily, Tori stared down at herself through the mouth of the costume, trying to make sense of whatever was happening to her. It felt strangely exhilarating, heart pounding, adrenaline surging through her body. She tried to shift her legs, feeling them pressing against each other in the confines of the tail. Tori could feel the skin of her thighs sticking together, flesh tugging as she tried to move, her legs fusing together into one.

   Amy watched with delight as the changes took hold of Tori’s body, not quite believing it would work. The bumps in the tail that had once been knees and feet faded away, leaving smooth scales, the bones of Tori’s legs disappearing amongst the changing flesh. Tori’s back arched, pelvis cracking and shifting, her insides adapting sublty to a more serpentine anatomy. Her spine pushed down through her body, new snake-like vertebrae stretching out along the length of her tail. A gasp escaped the hollow mask, Tori feeling a rush of sensation as her body steadily filled her tail, new nerves and veins entwining themselves through it. Amy grinned, watching the tail slowly fill out with the growing muscles, twitching and flexing with newfound strength.

   Tori struggled to make sense of the feelings at first, realising she could feel the rough carpet beneath the tail, the cool air blowing across her scales. She pushed herself up, new instincts curling her tail under her torso, new muscles shifting about under her skin.

   “Wow…” the soft gasp escaped her mask, feeling the changes working their way up her body. It felt like her spine was crawling, bone and cartilage warping into each other, ball joints forming to match the spine running through her tail. A few pops sounded as Tori’s ribs stretched further apart, her torso lengthening, new muscles growing around to support her flexible body. She swayed her body side to side, getting a feel for things, hands running down her body, across her hips. She could feel something stirring there, an opening in the scales, heart beating faster as her claws brushed over the slit.

   Tori blushed red, snatching her hands away, conscious Amy was surely still watching her… somewhere. She grew a little impatient, wanting the changes up hurry up and reach her head, her excitement only growing as she realised her hands were changing. Her nails lost under her scaled skin, she could feel the claws of the costume pressing into her, becoming a part of her. Awkwardly holding an arm up to the mask, peering through, Tori experimentally flexed her hand.

   Amy smirked, keeping low and out of view, not wanting Tori to see the giddy look on her face. She watched Tori admiring her new claws, fear gripping her for a moment. What if she didn’t like the changes? No, of course she would, this was awesome! A thousand thoughts ran through Amy’s mind, calmed only when she saw Tori flick her fingers, drawing the razor-sharp claws inside her.

   Finally, Tori could feel the changes progressing up to her neck, thick muscle growing, gasping as her throat opened wider. The top of the costume pressed tightly against her head, hair vanishing inside, her ears flattening completed. For a moment, she could hear nothing until something shifted either side, subtle new snake-like ears opening in her scales. Steadily, her face began to push forward into her new snout, her skull popping and cracking as it shifted to match her serpentine body.

   With her skull pushing forwards Tori realised her eyes were sliding out to the sides of her face, trying to make sense of her changing field of vision, noticing the green eyes of the costume drawing closer. Her nose flattened across her face, nostrils shifting smaller before pressing into the inside of the mask. It was a strangely comforting feeling, like her body was being made right, and whole. Her eyes became one with the green lenses, her irises growing wide, changing colour to a brilliant emerald. The lenses themselves faded, becoming more flexible, the membrane sliding away. Looking down over her own scaled snout, Tori watched the nostrils twitch slightly as she breathed in, only then realising she couldn’t smell anything.

   Tori could feel her mouth stretching out long and wide, pressing into her scaled maw. Sharp fangs settled amongst her own teeth, settling out along her length. She could feel the new fangs pressing into her jaw, old teeth growing more pointed to match. Inside, her tongue stretched out longer and finger, branching out at the tip. It flashed between her pointed teeth, forked ends tasting the air, sensing Amy’s arousal as she gazed up at Tori’s bestial beauty.

   “You knew this would happen, didn’t you?” Tori turned to face Amy, eyes glinting with predatory glee, latex scales lining her mouth parting to reveal a jagged grin. Her voice sounded strange coming from her snake-like mouth, a little deeper, her ‘s’ sounds drawn out by her flicking tongue. Looking down at her girlfriend, seeing her quaking slightly, Tori sensed her body heat rising.

   Amy squeaked, nodding slightly, enraptured by the sight of Tori. It was everything she’d dreamed of, and more. Amy’s eyes flicked over Tori’s body, taking in the length of her tail, the scaled breasts heaving on her chest, the snake-like visage now staring down at her.

   The serpent woman inched towards Amy, instinctively shifting her tail beneath her, gazing longingly at the human before her. She flexed the length of her tail, drawing it up around the pair of them, coiling it around Amy’s waist, gently squeezing her. Through her scales, she could feel Amy’s heart beating faster, sensing her fear and apprehension as she drew her closer to her face…

   Tori’s snout flashed forward, a blur of orange streaking towards Amy, stopping short to gently boop Amy’s mouth in a kiss. Amy’s fear melted away, giving way to lust as she felt the tip of Tori’s tail wrapping under her skirt, brushing across her thigh, reaching to tug at her panties.

   “If only there was some way I could repay you…” Tori smirked, gazing at Amy’s blushing face.

To be continued…