Russell… AKA Lisa

"Thank you for participating in the trial Russell." Luke said raising the nanite injector.

Russell pulled against the bindings on his wrists. He was paricipating but not voluntarily, tied naked to the doctors chair. "Luke, please... I didn't do anything to you," he explained, eyes focused on the needle. He had no idea what was in there but he suspected it would. Hangs his sex at the least. That's what they'd done to Luke.

Luke grinned. "Oh, you so deserve this..." he injected the nanites into Russel's arm. The effects were instantaneous. Russell's arm started to slim immediately, the changes moving out rapidly from there. Russell struggled vainly, shying away from the inevitable progress of the nanites. Lopsided from the injection point Russell grew smaller, slimmer, less muscular, softer. The changes flowed outwards as the nanites replicated and spread. The bindings holding him in the chair grew loose. He could feel his bones heating as they shortened and atrophied. He could feel his chest swelling. His sex dwindling, splitting, blooming, altering to become female. Worse he could see it - his once masculine body becoming small, sexy, curvy and completely feminine. Nipples growing fat on his hefty breasts. Her...

The urge to obey and be submissive grew strong within her as her brain chemistry altered. She tried to fight it. Tried to hold onto her sense of self. Hormones flowed into her mind. An unfamiliar urge took hold of her.

Luke undid her bindings and helped her stand. She stood unsteadily on much widened hips. Child bearing hips. She was quite buxom but short. "We're not done yet..." Luke advised as he turned her around and undid his pants, bending her over the chair. "You might recognise this body. I think you nicknamed it the breeder. A baby maker. You want a baby don't you Lisa?" Luke asked as he slide his manhood up her thigh.

Lisa shook her head in uncertain fear. But that urge grew. She widened her stance to allow him better access. "So the nanites will accelerate to pregnancy. The only thing I need to do is fertilise an egg..."

Lisa arched her back, heavy breasts swaying as she pushed back, her lips parting to allow him in. She moaned. She didn't want to do this on an intellectual level but what Luke said was true. She was a baby maker now. The urge to be impregnated, to become a mother was hard wired into her body and mind. She pushed back so his cock filled her. Then she started to rock her hips, sliding back and forth along his cock. It felt incredible. She needed more. She increased her pace, downward hanging breasts swaying, sweat beading her naked skin. It was addictive. The best sex ever. Her pussy started to throb. She was moaning like a bitch in heat. Then the first orgasm hit. She felt her legs weaken as she swooned in orgasmic bliss. Luke gripped her hips and kept going. She came again. Hot. Wet. Loud. Orgiastic. And then she felt him cumming. Filling her. Her eyes widened as she realised the nanites were at work inside her womb. She knew she was pregnant. Immediately. Luke slid out as a warm pleasure filled her belly.

"The pregnancy won't last too long. Your job Lisa is to document it. You are to take daily selfies to chart your progress. And after the first child there will be more..."

"Yes sir," she agreed meekly. She was pregnant. She was in shock.

Over the next month she documented her growing belly, her swelling breasts and increasing acceptance of her new role as a woman and mother. The hormones and mental changes ensure her happiness at the changes no matter her thoughts on them. And her body did swell. Her slim tummy grew with child, breasts plumping to make milk, ass rounding. She had no pains though. Her body was custom engineered to make babies. This was her purpose now.