Tails: Marissa’s wish

The coin soared, a shimmering disk of gold that caught the dim light of the bedroom. Simon watched it with wide, hazy eyes, her body still humming from the massive pressure filling her. She didn't even have the strength to reach out for it this time. The coin hit the carpet with a soft, muffled *thwack* and rolled a few inches before coming to a dead stop.

Tails.

"Only you and I are aware of the changes," Marissa breathed, her voice suddenly dropping an octave, vibrating with a newfound, masculine resonance.

The transformation hit her with a violent, exhilarating rush. Marissa let out a choked gasp as her hips shuddered, the familiar softness of her crotch suddenly erupting into something heavy and demanding. She felt the sudden, sharp growth of a shaft, the skin stretching tight as a thick, pulsing cock surged into existence, pushing through her underwear with an aggressive force. Her short's button popped and flew across the room like a bullet as a thick, pulsing weight forced its way out from between her legs.

"Oh god... oh wow," Marissa gasped, her voice sounding husky and predatory. She looked down at the massive, twitching erection that now dominated her lap, then looked back at Simon.

The sight of it triggered something visceral in Simon. The massive, static pressure of the dildo suddenly felt like a pale imitation—a cold, lifeless placeholder. With a sudden, desperate movement, Simon gripped the toy and yanked it out of her body with a wet, echoing *pop*, tossing it carelessly to the side of the bed. The emptiness that followed was instantaneous and agonizing, but it was quickly replaced by a magnetic pull toward her sister.

Simon’s eyes locked onto Marissa’s new addition. It wasn't just that it was there; it was the *way* it looked. There was something about the pulse of the veins, the deep hue of the skin, and the sheer, arrogant presence of it that felt hypnotic. Every second Simon stared, the attraction grew, pulling at her like a tide. It was an irresistible, gravitational force that made her own pussy throb with a needy, rhythmic heat. She felt a craving to touch it, to taste it, and to feel that same irresistible power filling her up for real.

"Marissa," Simon whimpered, her voice trembling and high. "I can't... I can't stop looking at it. It’s so... you're so irresistible. I just want to play with it. I *need* to play with it.

Marissa didn’t move. She stood there, leaning against the doorframe, basking in the sheer, raw power of the transformation. The masculine surge in her system had brought with it a level of confidence that was almost predatory, a commanding edge that made her chest swell. She looked down at Simon—small, flushed, and trembling on the bed—and a slow, knowing smirk spread across her face. The dynamic had shifted completely; the roles of dominance and submission had been rewritten in a single flip of a coin.

"You're practically begging for it, aren't you?" Marissa’s voice was a low, resonant rumble that seemed to vibrate in Simon's own chest. She didn't offer a hand or a gentle word. Instead, she stepped forward and stood over her, the massive, irresistible length of her new cock twitching just inches from Simon's face. "Well, don't just stare at it with your mouth open. Get down there. Suck it. Now."

The command hit Simon like an electric shock. Without a second of hesitation, she slid off the bed and onto her knees, her movements frantic and desperate. The scent of Marissa—now a heady mix of their shared sibling pheromones and a new, muskier masculine tang—overwhelmed her. Simon leaned in and wrapped her lips around the crown, a soft, needy whimper escaping her throat. As she began to suck, the sheer scale of the organ filled her mouth completely, stretching her cheeks and forcing her to breathe through her nose in ragged, shallow gasps.

Between the wet, sliding sounds of the act, Marissa let out a long, shaky exhale, her fingers tangling in Simon's strawberry blond hair, guiding the pace. "Tell me, Simon," Marissa groaned, her voice strained with pleasure, "how does it feel? How does it feel to have your sister's cock in your mouth?"

Simon couldn't even form a full sentence; she could only manage broken fragments between greedy, wet gulps. "Mmm... god... it's... the best... mmmph!" She pulled back for a second, her lips glistening, her eyes wide and glazed with a mix of desperation and euphoria. "sensation... I've ever had..."

Simon gets interrupted by Marissa pushing her cock back into her mouth, the thick shaft sliding over her tongue and hitting the back of her throat. Marissa’s hips gave a sharp, instinctive jerk, her voice becoming a strained, low rumble. "Don't stop sucking you bitch, just tell me...."

"It’s intoxicating ghhk—, I want more --- ghhk!" Simon managed to choke out, her voice muffled by the thick, pulsing girth filling her oral cavity. Marissa didn't give her time to breathe. She gripped Simon’s hair tighter, tilting her head back to create a better angle and thrusting her hips forward, sliding the shaft deep into Simon's throat. The sensation was visceral;

The sibling bond had mutated into something far more primal, a raw hunger that made her want to swallow every single drop of whatever Marissa was producing. She used her hands to guide the base, her fingers brushing against the heat of Marissa's balls, sending another jolt of electricity through her own feminine core.

The testosterone flooding Marissa’s system didn't just change her anatomy; it rewired her psyche. The warmth and sibling affection that usually defined their relationship were incinerated, replaced by a raw, aggressive need for dominance. As Simon’s lips worked frantically around the head of her cock, Marissa felt a surge of contempt and power that made her pupils dilate. She didn't just want the pleasure; she wanted the submission.

"Look at you," Marissa sneered, her voice a low, grating rumble that vibrated against Simon’s cheek. She tightened her grip on Simon’s hair, yanking her head back just enough to force her to look up. "A pathetic little slut, aren't you? Just a few minutes ago you were the big brother, and now you're nothing but an onahole for my cock."