Tell her you want her to finish the injections

"Finish them," you say, your voice emerging breathy and high. "I want all ten. I want to feel my ass grow."

Miss Velvet's entire body trembles at your words. Her right hand moves frantically between her legs, the lace of her panties soaked and clinging to her fingers as they work. She positions the final injection gun against the lower curve of your left buttock with her left hand, the metal cold against your burning skin.

"You're perfect," she gasps, her pink eyes wild and unfocused. "You're so fucking perfect, Candy."

The tenth needle pierces your flesh and the crimson serum floods in, completing the pattern of injection sites across both buttocks. The burning sensation multiplies immediately, all ten sites connecting into a web of heat that radiates through your entire lower body. You can't help the moan that escapes your lips.

That sound pushes Miss Velvet over the edge. She drops the injection gun onto the metal tray with a clatter and uses both hands now, one still working between her legs while the other grips the edge of the table for support. Her breathing becomes ragged, desperate.

"Feel it," she commands through clenched teeth, her gaze locked on your buttocks. "Feel what I did to you. Feel yourself start to grow."

It starts at the injection sites themselves, small bumps forming under the skin like mosquito bites. Within thirty seconds those bumps are expanding outward, the flesh puffing up as the serum triggers rapid cell division and fat deposition. Your buttocks are visibly growing, the curve becoming more pronounced with each passing moment.

"Yes," Miss Velvet moans, her fingers moving in frantic circles. "Yes, fuck, look at that. Look at your ass swelling up. Getting thick. Getting round."

The growth continues, steady and relentless. What were flat, masculine buttocks are now developing feminine contours—fuller, rounder, jutting outward. The sensation is overwhelming: burning mixed with pressure, tightness mixed with expansion, pain mixed with something disturbingly close to pleasure.

Miss Velvet's whole body goes rigid. Her eyes roll back and she makes a sound somewhere between a scream and a sob, her hand frozen between her legs as the orgasm hits her. She stays like that for several seconds, shaking, before her knees buckle slightly and she has to grip the table with both hands.

"Six hours," she whispers hoarsely, staring at your growing buttocks with glazed eyes. "Six hours and you'll have an ass like a Brazilian dancer. Thick and bouncy and perfect."

You surrender to stillness, watching the clock on the wall tick past eight o'clock. The transformation accelerates noticeably, the warmth in your buttocks intensifying into something that feels like your flesh is being kneaded from within.

Miss Velvet circles the table again, but this time her leather suit hangs completely open, the zipper pulled down to her navel. Her right hand slides back beneath the black lace panties, fingers working with renewed purpose as she watches your body reshape itself.

"This is my favorite part," she says, her voice thick with arousal. "When the growth hits its peak velocity. When you can actually see the changes happening in real time."

She's right. You can see it now—your buttocks visibly swelling larger with each passing minute, the curve pushing upward and outward, creating a dramatic shelf of flesh that would make sitting impossible if you weren't already strapped down. The skin stretches taut, then somehow accommodates the new volume, remaining smooth despite the rapid expansion.

"Three inches of projection now," Miss Velvet breathes, her fingers moving faster between her legs. "Maybe four. God, Candy, you're going to have the kind of ass that makes men walk into walls."

By 8:20pm, the pressure becomes almost unbearable. Your lower body feels impossibly full, weighted down, as if someone has attached heavy spheres to your pelvis. You test the restraints instinctively, not to escape but simply to adjust, to find some relief from the constant stretching sensation.

"Don't fight it," Miss Velvet commands, though her voice wavers as her own pleasure builds. "Let it happen. Let your body become exactly what I designed it to be."

The growth continues relentlessly. Your buttocks now jut out obscenely from your frame, creating proportions that seem almost anatomically impossible on your teenage-appearing body. Combined with the massive E-cup breasts and widened hips, your silhouette has become a caricature of hyperfemininity—exactly what Miss Velvet promised.

"Almost there," she moans, her hand working frantically now. "Almost at peak size. Just... fuck... just a little more..."

At 8:35pm, you feel something shift—not painfully, but definitively. The expansion slows, the pressure plateauing rather than continuing to build. Miss Velvet sees it too, her pink eyes widening as she watches the final swelling complete itself.

"Perfect," she gasps. "Absolutely fucking perfect."

Her whole body shudders as she brings herself to another orgasm, her free hand gripping the edge of the table while her other hand works between her legs. She stays frozen like that for long seconds, trembling, before slowly withdrawing her hand and zipping her suit back up with shaking fingers.