Mary Jane becomes Michael Jones and Peter Parker becomes Felicia Hardy

The last of the white mist sank back into the floor vents with a low mechanical sigh. The room went quiet except for the sound of both of you breathing too hard. Then the heat under your skin spiked.

MJ’s hand clamped down on your forearm hard enough to bruise. Her back bowed. A raw, startled sound tore out of her throat as her hips jerked and narrowed. You felt the shift through the contact bone and muscle rearranging under her clothes. The soft curve of her waist pulled inward. Her shoulders rolled forward and broadened with a series of wet, cracking pops. The hoodie stretched tight across a chest that was flattening and thickening at the same time. Her thighs pressed against yours, then pulled away as the muscle there swelled, denser, heavier. She slammed one palm against the metal floor and screamed, the sound dropping an octave halfway through as her throat changed shape.

“Peter fuck what’s ”

You didn’t get to answer. The same heat rolled through you in the opposite direction. Your hips flared outward so fast your jeans tore at the seams. You felt the bone shift, the sockets widening, the flesh above them rounding and softening into a pronounced curve. Your ass filled the ruined denim in a heavy, sudden weight that dragged your balance backward. You dropped onto your side with a choked cry. Your chest burned. The muscle there melted and reformed; soft, full weight pushed against the inside of your shirt, nipples tightening hard as the fabric pulled taut. Your shoulders narrowed. Your waist cinched. Every breath made the new breasts shift and ache. Your voice cracked high when you screamed, the sound thin and sharp in the metal room.

MJ was on her hands and knees now, hoodie half ripped down the back. The body under it was broad and solid thick arms, a wide back, the last traces of her old shape gone. Her face had sharpened. Jaw heavier. Hair shorter, darker at the roots like it was rewriting itself. She looked up at you and her eyes were wide, pupils still blown, but the face was male. Deep voice when she spoke again, strained.

“Your your hips. Peter, you’re ”

You couldn’t answer. Another wave hit. Your spine arched. Something cold and electric crawled up the length of it, then down your arms. Your fingers spasmed. When the pain eased enough to look, your hands were smaller, nails longer and sharper, the skin pale. Fine, almost invisible lines traced the insides of your wrists subtle, shifting patterns that caught the light when you moved. Your jeans were destroyed. The new curve of your ass and hips strained what was left of the fabric. Between your legs the change was finished; the absence of what had been there and the soft, sensitive heat that replaced it made you gasp and clamp your thighs together.

MJ crawled closer. Her new frame was heavy, powerful. One big hand hovered over your waist like she was afraid to touch. You felt the strength in her even without contact coiled, different. When she finally gripped your hip to steady you, her fingers sank into the soft flesh there and a bright, sharp jolt of sensation shot straight up your spine. Both of you flinched.

“Stop,” you managed. Your voice was higher, breathier. “Don’t everything’s still”

Another crack of pain cut you off. This one wasn’t bone. It was something else moving under the skin of your back and shoulders, light and quick, like muscle memory that wasn’t yours. Your balance shifted. The room suddenly felt smaller, the air thinner, every sound sharper. You pushed up onto your hands and the motion was too fluid, too precise. Your new center of gravity sat lower, hips and ass pulling your weight into a different posture. When you looked at MJ her eyes had changed too sharper, tracking your movement the way a hunter tracks prey. She flexed one hand and you both heard the faint, wet sound of something organic shifting under her skin.

The vents stayed silent. The gas was gone. What it had left behind was still settling.

MJ’s breathing had gone rough. She stared at her own hands, then at you at the hourglass shape of your body under the ruined clothes, the way your chest rose and fell, the long line of your legs. Her new voice came out low.

“I can feel it. In my blood. Like… webs. Or something that wants to stick.” She swallowed. “And you you’re moving different. Quieter.”

You tested it without meaning to. Shifted your weight. The motion was silent. Your nails caught the light. Somewhere deep in the new architecture of your body, bad luck and perfect timing sat coiled and waiting, the same way strength and instinct sat in hers.

You were both still on the floor. Still changing in the smaller ways skin settling, senses sharpening, the last of the pain fading into a low, constant hum under the surface. MJ’s hand stayed on your hip. Your smaller fingers had curled into the front of her torn hoodie. Neither of you moved to pull away.

Outside the locked door, distant voices called your names. The rest of the class was looking for you. Inside the room, the two of you stayed exactly where the gas had left you: one broad and solid and male, the other curved and sharp and female, both of you listening to the new rhythm of powers that didn’t belong to either of your old bodies while the changes finished writing themselves into your DNA.