Chapter 3: Sister's Surprise
The smell of sex hit Chloe first—musky, salty, thick in the still air of the apartment, layered over the familiar notes of burnt popcorn and stale energy drinks. Then came the sounds: wet, rhythmic slaps of flesh, a low, guttural grunting she’d never heard from Liam, and a high, desperate keening that was somehow, horrifyingly, familiar.
She pushed the door open with her hip, the six-pack of IPA swinging from her fingers. “I come bearing overpriced hops, you degenerates. Hope you’re decent, which you never—” The words died.
The living room was a disaster zone. A floor lamp lay shattered against the wall. The coffee table was shoved crooked, a half-empty mug upended, a dark stain spreading across the rug. And on the couch, a tangle of limbs and moving skin.
Liam, but not Liam—a mountain of muscle, his back a landscape of straining cords, sweat-slick and massive, completely blocking her view. He was pounding forward with a brutal, piston-like rhythm, his ass clenching with each thrust. Beneath him, a pair of slender, pale legs were wrapped tight around his waist, heels digging into the small of his back. Blonde hair—a cheap, brassy blonde—fanned out over a throw pillow.
Chloe’s brain stuttered, failed to process. Her fingers went numb. The six-pack slipped, hitting the floor with a crash of shattering glass and foaming beer.
Liam froze. The woman beneath him let out a frustrated whine. “Don’t stop, you fuckin’ tease, I was so close—”
That voice. That sarcastic, know-it-all cadence, now breathy and slurred with pleasure. Mack’s voice.
Liam turned his head, his profile now visible—the jaw like granite, the thick-rimmed glasses askew. His eyes, wide with panic and something else, something feral, met Chloe’s. He pulled back, his cock sliding out with an audible, wet pop. It was huge, ruddy and thick, glistening with slickness.
The blonde woman—girl, really— pushed herself up on her elbows. Her face was flushed, her makeup smeared. DD-cup breasts, bare and heavy with pink, hardened nipples, swayed with the movement. She blinked dazed, pleasure-drunk eyes at Chloe. A slick, wet smile spread across her face.
“Surprise, sis,” Mackenzie said, her voice a husky parody of her brother’s. She glanced down at the mess between her spread thighs, then back up at Chloe, pride and defiance in her gaze. “I’m hot now.”
Chloe couldn’t breathe. She stared at the place where Liam had just been buried, at the glistening, swollen flesh of her brother. Her vision tunnelled. The smell—copper, sweat, sex—was overwhelming. “Mack?” The name was a bare exhale. “What the fuck?”
Liam scrambled off the couch, his movements awkward in his new body, his enormous cock bouncing against his thigh. He fumbled for a cushion, holding it in front of himself, his face a mask of shame. “Chloe—it’s not—she started it, she was just there and talking and I felt so fucking weird and—”
“Oh, shut up, you loved it,” Mackenzie drawled, not bothering to cover herself. She leaned back, spreading her legs wider on the stained fabric, one hand trailing lazily through the wetness on her inner thigh. “He came in, like, two minutes. It was pathetic. But God, look at him.” Her eyes devoured Liam’s hunched form. “He’s a fucking god now. And me? I’m a goddamn trophy wife.”
Chloe’s own body betrayed her. A flush spread from her chest to her cheeks. Her yoga pants, suddenly, were unbearably tight. She couldn’t tear her eyes away from Mackenzie’s exposed core, the dark blonde curls plastered slick, the pink folds swollen and used. From the sheer, obscene evidence of it. This was her brother. This was Liam. Her brain shattered and reformed around the image.
“Explain.” The word was flat, cold. “Now.”
Mackenzie sighed, a theatrical, put-upon sound, and sat up fully. She reached for Liam’s discarded t-shirt—a band tee that now looked like a child’s garment on him—and wiped herself casually before pulling it over her head. It barely covered her nipples. “We don’t know. One minute I’m me, the next I’m… this. And Chad here,” she jerked a thumb at Liam, “got huge. We were testing things. It got… hands-on.”
“Testing things,” Chloe repeated, her voice hollow. She looked at Liam.
He looked like a gargoyle caught in headlights, all that new muscle tensed for flight, the cushion held like a pathetic fig leaf over his still-hard cock. The sickly yellow light from his desk lamp in the den spilled into the living room, glinting off the sweat on his shoulders and highlighting the sheer absurdity of the scene: the shattered beer bottles, the upturned furniture, her brother lounging half-naked in a used t-shirt.
“Testing things,” Chloe repeated, the words tasting like ash. “You were fucking. On the couch. That I sat on last Tuesday.”
“It needed to be broken in,” Mackenzie shrugged, the movement making the thin cotton strain across her chest. She examined her nails, then flicked a glance at Chloe. “Don’t look so constipated. It’s just a body. A really, really good one.” Her hand slid down the shirt, palming her own breast, thumb rubbing slow circles over the nipple. “See? Functional. Everything works. Better, even.”
Liam made a strangled noise. “Stop touching yourself.”
“Why? You liked it ten minutes ago. You were sucking on them like a baby with a bottle.” She laughed, a bright, cruel sound. “Chloe gets it. Look at her. She’s staring at your dick, Liam. She can’t help it.”
Chloe forced her eyes away, her cheeks burning. She was staring. The thick, veined length of him, barely concealed, was a magnet for her gaze. It was monstrous. It was fascinating. A hot, shameful pull tightened low in her belly. “I’m staring because this is a fucking nightmare. Mack, what is wrong with you? Your voice… your face…”
“I don’t know, Chloe,” Mackenzie said, the flippant tone fading for a second into something quieter, almost lost. She pulled her knees up to her chest, the vulnerable gesture at odds with her vulgarity. “Lexi sounded good. In my head, when it was happening. Lexi. And Liam here,” she jerked her chin, a ghost of Mack’s old smirk returning, “definitely thinks I’m hot.” She paused, her eyes narrowing at Chloe’s chest. “But I know we’re definitely not sharing bras. You’re, like, a B-cup on a good day. These things need architecture.”
The insult was so petty, so perfectly Mack, that it broke the paralysis. Chloe stepped over the foaming puddle of beer, her sneakers crunching on glass. “Get up. Both of you. We need to figure this out.”
“Figure what out?” Mackenzie stayed curled on the couch. “I feel amazing. I came three times. He might be an anxious wreck, but the new equipment is first-rate.”
Liam finally moved, shuffling sideways toward the hallway like a crab. “I need pants. Pants are good. Pants are a concept I support.”
“Stop,” Chloe commanded, and the authority in her voice made him freeze. She pointed at Mackenzie. “You. Stop talking about coming. You.” She pointed at Liam. “Stop pretending you’re not a part of this. What happened? Start from the beginning. Before the… couch.”
Mackenzie sighed, a long, exaggerated exhale, and launched into a disjointed narrative about pizza, energy drinks, a blinding pain, and waking up on the bathroom floor changed. She described the reverse-transformation in crude, graphic detail—the feeling of his cock retracting, the wet snap of his hips, the shocking weight of new breasts. As she spoke, her hands kept wandering, stroking her own thighs, cupping her jawline, as if confirming the reality.
Liam stood by the shattered lamp, his massive arms crossed, staring at the floor. He flinched when Mackenzie described the size of his new cock, a faint, pained groan escaping him.
Chloe listened, her mind grappling with the impossible. Her eyes kept drifting to Liam’s body, to the powerful lines of him, to the faded comic book logo stretched taut across his deltoid. The shy, skittish man she’d carried a torch for since college was gone, replaced by this towering, brutish sculpture of muscle and silent torment. And her brother was preening on a sex-stained couch.
“So, you have no control over it?” Chloe finally interrupted. “It just… happened. And stopped.”
“Seems that way,” Mackenzie said. She uncurled herself and stood, the t-shirt riding up to expose the full curve of her ass. She walked—a hip-swaying, practiced walk that was utterly alien—to the mirror above the fireplace. “Jesus, I’m pretty.” She turned, posing. “What do you think, sis? Should I go blonde for real? This wig is trash.”
“It’s not a wig,” Liam mumbled, still staring at the floor.
“What?”
“Your hair. It’s not a wig. It grew. I watched it.”
Silence descended, thicker than before. Mackenzie’s hands flew to her hair, fingers digging into the roots, pulling as if to yank it free. It didn’t budge. Her breathing hitched. The facade of smug confidence cracked, revealing raw, animal panic beneath. “It’s… attached.”
Chloe saw the terror flash in her brother’s eyes—Mack’s eyes, in this strange, beautiful face. For a second, she was just her sibling, scared and lost. Then Mackenzie blinked, and the mask slammed back down. “Whatever. It’s hot. I’m keeping it.”
“We can’t keep anything,” Liam said, his voice a rumbling shockwave in the quiet room. He finally looked up, meeting Chloe’s gaze. His eyes were the same hazel, but drowned in a new landscape of bone and muscle. “What if it happens again? What if I… shrink back? What if he changes into something else? What if we’re contagious?” The words tumbled out, fueled by a familiar, neurotic energy now housed in a body that could probably punch through a wall.
The practical horror of it settled on Chloe. She looked at the destruction, at their altered forms, at the sheer, reality-bending wrongness of it all. The authorities? A lab? They’d be dissected.
“Okay,” she said, the yoga-instructor calm surfacing through the shock. It was a flimsy raft, but she clung to it. “Okay. First, we clean this up. Every trace. Liam, put on actual clothes. Mack—Lexi—whatever—find something that covers more than a napkin. Then we talk. No more touching. No more… testing.”
Mackenzie pouted, a full-lipped, grotesque expression. “You’re no fun.”
“This isn’t fun!” Chloe’s shout surprised them all. The echo hung in the air, mixing with the smell of sex and spilled beer. She lowered her voice, trembling. “This is my brother and my… friend. This is something I can’t understand. So we will be calm. We will be smart. Or so help me God, I will walk out that door and you two can explain your new parts to the world alone.”
The threat landed. Liam nodded vigorously, already moving toward his bedroom. Mackenzie watched Chloe, a calculating look in her eyes that was entirely new. She smiled, slow and knowing.
“You’re staying, though,” Mackenzie said. It wasn’t a question.
Chloe looked at the broken glass, the stained couch, the impossible people in front of her. She thought of Liam’s terrified eyes in that powerful face. She thought of the slick, heated ache between her own thighs that hadn’t faded since she’d walked in.
“Yes,” she said, the word final. “I’m staying.”