The Swapping Device
Copyright© 2025 by JohnManTD
Chapter 5
Erotica Sex Story: Chapter 5 - By luck (or fate) James stumbles onto a magical device that allows him to swap anything with anyone. Body parts, personality traits, breasts, entire bodies... Follow him on his journey of self-discovery as he navigates the world with this new find. This is chapters 1-5 of my mainline story. New chapters are released weekly to my Patreon which is generally 2 chapters ahead of the public.
Caution: This Erotica Sex Story contains strong sexual content, including Ma/Fa Ma Fa Mult Consensual Mind Control NonConsensual Lesbian BiSexual Heterosexual Shemale TransGender Fiction Science Fiction Body Swap Magic Polygamy/Polyamory Exhibitionism Lactation Masturbation Oral Sex Safe Sex Sex Toys Tit-Fucking Big Breasts Body Modification Size Small Breasts Transformation
The sauna’s heat lingers on my skin like a lover’s breath as Sam and I step out, the air thick and heavy, my body still thrumming from the steam. I’m adjusting the hem of my crop top, feeling the way my breasts shift with every move, when Sam—stocky and vibrating with that manic glee of his—grabs my arm and yanks me down the hall. His girl-voice, high and giddy, cuts through the post-sauna haze. “Look at this, dude. Yoga class. Women only.”
I follow his gaze through the glass door at the end of the corridor. The studio’s alive with motion—a class must’ve just wrapped, because women are spilling out, sweaty and chatting, while a fresh group filters in. Mats unroll, leggings hug curves, and sports bras cling to toned chests. It’s a sea of feminine bodies, all gearing up to twist and stretch. Sam’s practically drooling, his eyes darting like he’s mapping every inch of potential.
“Perfect opportunity,” he says, grinning wide enough to show teeth. “Come on.”
I hesitate, shifting my weight. My booty shorts ride up, and I tug them down, hyper-aware of how my ass jiggles—a constant reminder of this lush, unfamiliar body I’m still breaking in. “Yoga? Seriously? I’ve never done it, Sam. Not as a guy, and sure as hell not like this.”
He rolls his eyes, crossing his arms over his modest B-cups. “So what? You’re a girl now. Blend in, stretch a little, watch some hotties bend in sexy ways. It’s a win-win.”
I snort, but the idea’s already snaking through me. All those women, their bodies flexing and arching—it’s hard to argue with the appeal. My pulse ticks up just picturing it. “Yeah, okay,” I mutter, pushing the door open. “But if I look like a dumbass, I’m blaming you.”
We sign up at the desk, the instructor—a tall, willowy woman with a topknot and a Zen vibe—handing us mats and pointing us to the back. “Just follow along,” she says, her voice like a lullaby. “No pressure, ladies.”
Sam picks a spot near the middle, already scoping the room like a predator. I unroll my mat beside him, bending to smooth it out and feeling my breasts sway under the crop top. The studio’s warm, humming with soft chatter and a faint lavender scent. I glance around—most of the women are fit, their bodies sculpted and confident, but it’s not all gym rats. A curvy girl near the front catches my eye—pudgy, with a soft belly spilling over her leggings and thighs that could crush a melon. She’s stretching, though, folding her legs into angles that defy physics, her face calm like it’s nothing.
Sam nudges me, whispering, “See? Even she’s got moves. You’ll be fine.”
I nod, but I’m not so sure. I try a basic stretch, reaching for my toes, and—fuck me—my hamstrings lock up tight, screaming like they did back in my old body. I barely get past my knees, my fingers dangling uselessly, my thick thighs trembling. Sam’s watching, his smirk growing. “Dude, you’re stiff as hell.”
“Shut up,” I snap, straightening up. “It’s not my fault. These curves—I thought they’d help or something.”
He laughs, loud enough that a few heads turn. “Curves don’t bend, genius. Look at her.” He nods toward the pudgy girl, now pretzeled into some insane pose. “It’s not the body. It’s you.”
My cheeks burn. I thought being a woman might give me an edge—aren’t girls supposed to be flexible? But nope, I’m still a brick. “I’m done,” I mutter, rolling my mat up. “This is humiliating.”
Sam grabs my wrist, pulling me back down. “Don’t wuss out. Just swap flexibility with someone. Swap back later. Easy.”
I blink, the idea hitting like a spark. “Swap flexibility?”
“Yeah,” he says, nodding toward the front. “Pick a bendy one, hit the button, and you’re golden. No one’s gonna care.”
I chew my lip, scanning the room. It’s reckless—another tweak, another risk—but the class is about to start, and I don’t want to spend an hour flailing like a fish. My eyes lock on a petite girl up front—tiny, gymnast-build, her body sinking into a deep lunge like it’s effortless. She’s the most flexible here, hands down.
“Alright,” I whisper, fishing the remote from my bag. I select “flexibility” and “balance,” targeting her and me. Sam’s hand brushes mine, gripping the remote so he’s in the loop. I hit the button.
A faint zzzztttt hums, and a warm tingle races down my spine, spreading through my arms, my legs, my core. I roll my shoulders, testing it—suddenly, my body feels loose, alive, like I’ve been stretching all day. I reach down again, and my fingers glide past my toes, my back bending smooth and easy. Holy shit.
Sam’s eyes widen. “Did it work?”
I grin, standing tall. “Oh, it worked.”
The instructor claps her hands, her voice cutting through the chatter. “Let’s start with a sun salutation. Inhale, reach up...”
I follow, my arms sweeping overhead, my back arching deep and fluid. When I fold forward, my nose brushes my shins, my palms flat on the mat. It’s unreal—my muscles stretch like taffy, strong and pliant, my breath syncing with every move. Beside me, Sam’s a disaster, his stocky frame wobbling as he grunts through the poses, his B-cups jiggling with every shaky shift.
We flow through it—downward dog, plank, cobra—and I’m in my element. My hips lift high, my ass perked in the air, and I catch my reflection in the studio mirror. The crop top clings to my chest, my breasts pressing together as I move, and my booty shorts ride up, showing off the curve of my thighs. Sweat beads on my skin, trickling between my cleavage, and I feel good—sexy, powerful, like I belong.
Sam’s not faring so well. “This is brutal,” he mutters, his face red as he stumbles out of warrior two. “How are you making this look easy?”
I smirk, sinking deeper into a lunge, my knee brushing the mat. “Borrowed talent, remember?”
“Cheater,” he huffs, but he’s grinning through the strain.
The class ramps up—crow, headstands, splits—and I nail every damn one. My body twists and bends like it’s liquid, my curves shifting with each pose. In crow, my knees perch on my arms, my balance rock-solid, and when we hit headstands, I kick up smooth, my core tight, my legs arrow-straight. The splits come next, and I slide into them effortlessly, my thighs splaying wide, my pussy grazing the mat as I lean forward. Sweat slicks my skin, my breath steady, and I feel alive, electric.
The other women steal glances, their eyes flickering with quiet awe. I catch the petite girl up front—the one I swapped with—struggling through a basic forward fold, her body stiff and awkward. She doesn’t react, though; to her, this is normal. To me, it’s a goddamn miracle.
Near the end, the instructor calls for a final challenge: a full split with a backbend. Most of the class opts out, shaking their heads with tired laughs, but I step up. My heart pounds—not nerves, just raw excitement. I slide my legs apart, sinking lower, lower, until my thighs kiss the mat, my groin flush with the floor. Then I arch back, my spine curving deep, my breasts thrusting skyward as my hands reach behind me. It’s a spectacle—my body stretched to its limits, every curve on display—and I hold it, steady, feeling like a queen.
Sam’s jaw drops. “Holy shit, Jamie,” he whispers, slipping my girl-name out without a thought. “You’re unreal.”
I laugh, easing out as the class claps lightly. The instructor nods my way, her calm mask cracking with a flicker of respect. “Great work today, everyone. See you next time.”
We roll up our mats, and I’m buzzing—adrenaline, pride, something hotter coiling in my gut. Sam’s still gawking, half-impressed, half-envious. “That was insane. You’re keeping that, right?”