"Fuck… Gwen… please…"
The words tore from Ben's throat, a raw, guttural sound that didn't sound like his own. It was higher, laced with a frantic, fluttering vibration. His back was a taut arch, pressing the soft, lavender curves of his alien form into the scratchy fabric of the old motel bedspread. His fingers—long, slender, tipped with delicate claws—were tangled in the fiery red hair between his legs.
Gwen's mouth was a brand of wet, relentless heat on his pussy.
Not his pussy. Her pussy. The thought was a dizzying spiral in the storm of sensation. Hers. Because the form was female, a sleek, athletic alien he'd dubbed 'Lavender Lightning' in his head. The Chaquetrix hummed warm and insistent against the skin of his—her?—chest, a constant reminder of the transformation.
"Please what, cuz?" Gwen's voice was a muffled, vibrating purr against his soaked folds. She didn't pull away, her tongue still working in slow, broad strokes that made his hips jerk off the mattress. "Use your words. Tell me what you need."
He couldn't. The language center of his brain had short-circuited, replaced by a white-noise static of pleasure. His pussy was a throbbing, swollen ache of need, the alien anatomy hypersensitive in ways his human body had never been. The lips were a plump, deep violet, already glistening and parted, revealing the glistening, deeper purple interior. Gwen's tongue felt huge, rough, and perfect as it speared inside, then curled up to rub a spot that made stars explode behind his eyes.
"Guh… nngh…" He was babbling. His legs, long and toned with lean muscle, trembled where they were hooked over Gwen's shoulders. The view was obscene, pornographic. Gwen, his cousin, knelt between his spread thighs, her own jeans long discarded. The thick, impressive length of her cock—a flushed, veiny pink—lay heavy against her stomach, leaking a clear, sticky strand onto the motel carpet. Her balls, a tight, hairy sac, swayed with the motion of her feasting.
It had started with a whisper. A week ago.
*
The summer sun was a hammer on the back of Ben's neck as he poked through the junk in the rusted-out shell of Grandpa Max's old RV, parked behind the newly reopened Null Void salvage yard. The Omnitrix—or what he'd thought was the Omnitrix—had been a sleek, black-and-green gauntlet in a fallen meteorite chunk. This thing was different. Smaller. A brooch, almost. Silver and intricate, with a central, heart-shaped chamber that pulsed with a soft, rose-gold light. It didn't attach to his wrist. When his fingers brushed it, it snapped to his chest with a magnetic click, the surface molding to his sternum.
The Chaquetrix. The name appeared in his mind, not as a sound, but as a concept. A translator. A key.
His first transformation was a shock of painless, electric warmth. His body melted and reformed in a cascade of light. When it cleared, he was staring at his hands—now covered in fine, peach-colored fur with pads on the fingertips. He was shorter. Lighter. And when he looked down, two pronounced, soft mounds pressed against the fabric of his t-shirt. A high, panicked sound escaped his throat. It was a girl's voice.
"Ben?"
He'd spun, the motion fluid and graceful. Gwen stood at the edge of the RV, a bag of chips frozen halfway to her mouth. Her eyes, a sharp blue-green, widened. They didn't widen in horror, or confusion. They widened with a sudden, laser-focused intensity. Her gaze swept from the fur on his arms, to the new swell of his chest, down to the undeniable curve of his hips in now-too-baggy jeans.
"Whoa," she breathed, the word full of air. The chips were forgotten. "What… what is that?"
"I don't know!" Ben's new voice was a melodic chirp. "It's not the Omnitrix! It made me a… a girl!"
Gwen took a step closer, her head tilting. A slow, intrigued smile played on her lips. "A cat girl, looks like. Look at the ears." Ben's hands flew to his head, finding two fuzzy, triangular appendages twitching atop his skull. "Cute."
"It's not cute! It's a malfunction!"
But Gwen wasn't listening. She was circling him, that analytical look she used on complicated homework problems now applied to his new body. "The structure is completely different. The pelvic tilt, the shoulder width… it's a perfect sexual dimorphism shift. Not a costume. Actual, biological transformation."
"Can you not sound so fascinated?" Ben squeaked, trying to will the brooch to let him go. It hummed, stubborn.
"Why not? It's the most fascinating thing I've ever seen. Here, try to change back. Think 'human.'"
He did. The warmth surged again, and he collapsed back into his own lanky, eighteen-year-old body with a gasp. The relief was instant, followed by a weird, hollow feeling. Gwen's smile didn't fade. It turned speculative.
"Fascinating," she repeated, softer.
The next few days were a blur of testing. The Chaquetrix had ten slots, each one stabilizing into a different female alien form. A rock-like being with crystalline growths. A winged, slender creature with iridescent skin. A hulking, four-armed brute with tusks. All female. Every time he transformed, Gwen was there, watching. Her initial scientific curiosity began to simmer with something else. She'd ask him to hold forms longer. She'd request specific ones. She'd get closer, under the guise of 'examining the physiological changes.'
Her touches started as clinical. A hand on his new, rocky bicep to 'test density.' Fingers brushing the shimmering skin of his winged form to 'feel the texture.' But her breath would hitch. Her cheeks would flush. And Ben, trapped in these foreign, sensitive bodies, would feel a responding heat that was absolutely not clinical.
The corruption was slow, quiet, and entirely Gwen's doing.
It was two nights ago, in this very motel room on their aimless road trip. Ben was in his 'Lavender Lightning' form, trying to see how fast he could vibrate his molecules. Gwen was sitting on the edge of her bed, pretending to read a book. He could feel her stare like a physical weight.
"You know," she said, her voice casual, "I've always been into aliens."
Ben stopped vibrating. "Yeah, me too. That's why we're on this trip."
"No." She closed the book. "I mean… I'm into aliens. Romantically. Sexually." She looked right at him, her gaze dropping to the sleek, powerful lines of his lavender body, the subtle swell of the chest, the curve where waist met hip. "I'm a lesbian, Ben. And alien girls… they do it for me. A lot."
The air in the room thickened. Ben's alien heart hammered against the Chaquetrix. "Oh." It was all he could manage. A thousand implications crashed together. Gwen. His cousin. Looking at him—at this her—with open, hungry desire.
"And you," she continued, standing up and taking a slow step towards him. "In these forms… you're not really my cousin, are you? You're a new person. A beautiful, alien girl." Her hand came up, not touching, just hovering near his cheek. The energy field around his lavender skin crackled towards her fingers. "Do you feel like Ben right now?"
He didn't. He felt powerful, graceful, electric. And desperately, confusingly aroused. The form came with its own hormonal cocktail. "I… I don't know."
"Let's find out," she whispered.
Her kiss wasn't gentle. It was claiming. Her lips were soft but demanding, her tongue sweeping into his mouth. And Ben—the alien girl—met it with a hunger that shocked him. His hands came up to grip her shoulders, claws pricking her shirt. The taste of her, mint and something uniquely Gwen, flooded his senses. When she pulled back, they were both breathing hard.
"Definitely not just Ben," she murmured, her thumb stroking his lower lip. Her other hand slid down, over the smooth, firm plane of his stomach, lower, until her fingers brushed the seam of the simple shorts he wore. Even through the fabric, the contact was a lightning bolt. He gasped, a high, shaky sound.
"Gwen… we can't…"
"Why?" Her fingers pressed, rubbing a slow circle. A damp spot immediately bloomed on the fabric. "She wants to. I want to. Who's getting hurt?" Her eyes locked on his, challenging. "Be honest. In this body, do you want me to stop?"
The truth was a tremble in his gut. The alien body screamed NO. Every nerve ending begged for more. The human mind, Ben's mind, was a shrinking island of protest in a rising sea of sensation. He shook his head, a tiny, helpless movement.
Gwen's smile was triumphant. "Good girl."
*
"I said, use your words, cuz." Gwen's voice dragged him back to the violent present. She lifted her head, her chin slick with his juices. Her eyes were dark, pupils blown. "Tell me what you need, or I stop."
The threat was unbearable. "Don't stop! Please, don't stop!" Ben begged, his voice cracking. "I need… I need to come. Please, Gwen, let me come!"
"Since you asked so nicely." She dipped her head back down, but her approach changed. No more broad strokes. Now her tongue became a precise, wicked point. It flickered over the swollen, violet nub of his clit, rapid-fire taps that made his whole body seize.
"Ah! Ah! Right there! Right THERE!" he screamed, his claws tearing the bedspread. The coil in his lower belly wound tighter, a spring of pure tension. Gwen hummed against him, the vibration traveling straight up his spine. One of her hands came up, two fingers sliding into his sopping entrance with a wet, easy schlick. They curled, searching, and found a spongy, textured spot inside that made his vision whiten at the edges.
"There it is," Gwen growled, her voice thick with satisfaction. She pumped her fingers, a steady, deep rhythm, while her tongue continued its relentless assault on his clit. "Gonna come for me? Gonna squirt all over my face, you pretty little alien slut?"
The degradation, paired with the sinful skill of her touch, shattered him. The orgasm didn't build—it detonated. A raw, shattering wave of pleasure ripped through the lavender body. His back arched impossibly high, a silent scream on his lips before sound returned as a broken, continuous wail.
"Gwen! GWEN! FUUUCK!"
His pussy clenched around her fingers, rhythmic, desperate pulses. And then, with a guttural groan from Gwen, a hot gush of fluid erupted from him, not just a trickle but a sudden, splashing torrent. It soaked her chin, her neck, the front of her tank top with a sound like a splash of water. Splurt. Squirsh. The scent, musky and sweet, filled the room.
"Yeah… fuck, look at that," Gwen moaned, riding out the pulses, drinking him in as he spasmed beneath her.
The hypersensitivity was instant and agonizing. As the last tremors shook him, her tongue, still lazily circling his oversensitive clit, became torture. Pleasure twisted sharply into a bright, electric pain. He shrieked, his body trying to jackknife away, but Gwen's hands clamped on his thighs, holding him open, immobile.
"Nuh-uh," she chided, her voice a dark sing-song. "We're not done. One's not enough for a good girl."
"No! No, please, it's too much! I can't!" Ben sobbed, tears leaking from the corners of his eyes. His hips twitched in helpless, aborted movements, trying to escape the unbearable stimulation. Every nerve in his pussy was a live wire, screaming in protest. But beneath the pain, a new, shameful heat was already stirring. The Chaquetrix on his chest pulsed, as if feeding on the overload.
Gwen ignored his pleas. She lowered her mouth again, this time sucking his entire swollen clit into the heat of her mouth, applying a gentle, sustained pressure. The pain blurred, mixed with the rekindling embers of pleasure. A broken, continuous moan was torn from Ben's throat.
"See? You can take it. You're taking it so well," Gwen whispered against his flesh, the praise a counterpoint to her merciless actions. Her fingers, still soaked inside him, began to move again, a slow, twisting motion. "Such a good, filthy girl. Coming all over your cousin. You love it, don't you? Tell me you love it."
Ben's mind was mush. The corruption was complete in this moment. The human guilt, the taboo, it was drowned under the tsunami of physical sensation. "I love it!" he wailed, the confession ripped from him. "I love it, I'm sorry, I love it!"
"Good." Gwen pulled her fingers free with a wet pop and finally released his throbbing clit from her mouth. He collapsed back onto the bed, boneless, panting, a twitching mess. She stood up, looming over him. Her cock, fully erect now, stood out thick and angry, the head glistening. She stroked it slowly, her eyes drinking in the sight of him—lavender skin flushed with deeper purple, pussy gaping and glistening, his own release pooled on his stomach and thighs.
"Now," she said, her voice husky with command. "You're going to beg for this. You're going to beg for your cousin's cock to fill up that pretty, used little pussy."
Ben's alien eyes, wide and glassy, stared at the sheer size of her. It looked massive, intimidating. A deep, primal part of this form clenched with want. The converted size queen trope wasn't just a concept; it was a biological rewrite. The sight of that impressive length and girth made his human memories of anything else seem pathetic, inadequate. He needed it. He craved it.
"Please…" The word was a hoarse scrape. He spread his trembling legs wider, an open, vulnerable invitation. "Please, Gwen. Daddy… please fuck me. I need it. I need you to fill me up. I can't… I can't think straight without it. Please!"
Gwen's expression softened for a fraction of a second, something like genuine awe in her eyes, before it hardened again with lust. "Since you asked so prettily."
She didn't kneel. She grabbed his hips, her grip firm, and yanked him to the very edge of the bed. His ass hovered in the air, his back still on the mattress. She positioned the broad, slick head of her cock at his dripping entrance. She rubbed it up and down, smearing his juices, teasing the swollen lips, making him whimper with renewed need.
"Look at me," she ordered.
Ben forced his gaze up to hers. She held it, her blue-green eyes blazing, as she pushed forward.
The stretch was immense, immediate, and breathtaking. Ben's mouth fell open in a silent 'O'. The alien pussy was tight, but incredibly elastic, designed to accommodate. It yielded to the relentless pressure, stretching wide around the invading girth. The sensation of being filled, so completely and deeply, was overwhelming. He felt every ridge, every vein on her shaft as it sank deeper, an inch at a time.
"Oh… god…" he finally moaned, his head thrashing side to side. "So… big…"
"You feel that?" Gwen gritted out, her own control fraying. "That's all me. Stretching you open. Taking what's mine." She bottomed out, her hips flush against his ass, her balls resting against his skin. They were both still for a moment, panting, connected. Ben could feel her heartbeat in his core.
Then she moved.
The first thrust was a slow, deliberate withdrawal until just the tip remained, then a hard, driving slam back home. The impact jolted through Ben's body. A punched-out gasp left him. The second thrust was faster. Then faster still.
Soon, she was fucking him in earnest, a hard, steady, pounding rhythm. The sound was obscenely wet, a rhythmic slap-slap-squish of flesh and fluid. The bedframe groaned in protest, hammering against the motel wall. Ben's world narrowed to the brutal, perfect pistoning of her cock inside him. Each drive hit that same magical, textured spot, lighting up his nerves like a pinball machine.
"Yes! Yes! Right there! Don't stop! Fuck me!" he chanted, his voice rising with each thrust. His claws scrabbled at her back, scoring red lines through her tank top. His legs wrapped around her waist, locking her in, pulling her deeper. The domination was absolute, but in his abandon, in his desperate, greedy participation, he was somehow stealing it back. He was making her fuck him like this, with his pleas, his movements, his hungry cunt.
"You like that, you size queen?" Gwen grunted, sweat dripping from her brow onto his chest. Her pace became erratic, harder, faster. "You love being split open by your cousin's big dick? Tell me you love it!"
"I love it! I love your dick! It's the only thing that fits me now! Fuck!" Ben screamed, the confession utterly debasing and utterly true. The coil was winding again, tighter and hotter than before. His pussy fluttered and clenched around her, milking the shaft.
Gwen's rhythm broke completely. She slammed into him, hard and deep, and held there with a shuddering groan. Ben felt the hot, thick pulse deep inside him as she came. A flood of warmth filled him, spurting in heavy, rhythmic waves. The feeling of being claimed, of being filled, tipped him over his own edge.
His second orgasm was even more violent than the first. It wasn't a squirt this time, but a series of deep, internal convulsions that clamped down on Gwen's still-spurting cock. A wordless, shrieking cry was torn from his lungs, his body bowing off the bed. The pleasure was so intense it bordered on pain, a full-body electrocution of bliss.
Gwen collapsed on top of him, both of them slick with sweat and cum. She was still inside him, softening, but she made no move to pull out. The post-orgasm creampie continuation was a heavy, intimate warmth. Ben could feel her release leaking out around the edges, a sticky trickle down his ass crack. He was hypersensitive again, every tiny movement sending shivers through him, but it was a sweet, full ache now.
For a long moment, there was only the sound of their ragged breathing and the hum of the cheap air conditioner. Gwen nuzzled into the crook of his lavender neck.
"See?" she mumbled, her voice thick with exhaustion and satisfaction. "Told you you weren't just Ben."
Ben, floating in a post-coital haze, his human thoughts fuzzy and distant, could only make a soft, agreeing sound. The Chaquetrix pulsed warmly against his chest, a silent accomplice. He was changed. Corrupted. And as the warm seed continued to seep from his well-used pussy, he knew, with a terrifying thrill, that he wanted more.