Author's note – this is the second instalment in a series of 5. In addition to the breast expansion, futanari, lactation and cum inflation featured in the previous instalment, this story ups the weird with the addition of nipple penetration and macrophilia. More of that corrupting Japanese hentai influence.
Kelly and Gemma fell into the dark laboratory, piercing the silence with their drunken laughter. It was a miracle that they were still upright. So far tonight they'd poured enough cocktails down their necks to flatten an elephant, and had been in the process of migrating to another nightclub when Kelly's suggested shortcut led them past a mysterious-looking door that they couldn't resist the urge to investigate. Well, Kelly couldn't resist the urge. As usual, Gemma advised caution, but as usual, Kelly's sense of adventure won out.
Both girls were dressed for a night of drinking and debauchery, their bodies packed into tight tops and short skirts, both of them perched precariously on heels that would have been tricky to handle even when sober, wearing push-up bras to make their B-cup breasts look more impressive. On the whole, they were both very similar in appearance – a little shorter than average, pale skin, dark hair. Years of drinking booze, eating fast food and getting not enough exercise (except for sex) meant that neither of them were what you would describe as thin, though neither were they obese. Just a little on the plump side.
"We really should leave. We don't know what this is." slurred Gemma.
"Ssssh" replied Kelly, staggering around the tables, inspecting the various scientific equipment and idle computers. She found one with a mouse, gave it a wiggle, and the screen blinked to life.
"What are you doing? Maybe you should be not doing... what you're doing."
Kelly ignored Gemma. A user interface had appeared on the screen, prompting her to click a button to start the RIBRUNT experimental program. How could she resist? She clicked the button, and a warning popped up. It looked really important, so she ignored it and clicked continue. Another warning popped up, twice the size of the previous one. Continue.
To both of their surprise, a figure appeared beside the desk with absolutely no fanfare whatsoever. A blue, hologrammatic woman. She glowed so brightly that she illuminated the centre of the room, and she spoke.
"Good evening. I am Wendy, the program interface module. To begin the program, all subjects and controllers must ingest a single measure of the nanosoup."
On the desk, a large piece of apparatus hissed open in a cloud of dry ice, revealing a number of perspex cylinders containing a benign-looking red syrup.
"Wheeee!" trilled Kelly, "shots!"
Quick as a flash she snatched up two, passed one to Gemma, popped the lid on her own, and tipped it back. Gemma, caught up in the moment, did likewise. As the red liquid poured down her throat, she briefly came to her senses and thought to herself "why the fuck did I just do that?" Too late now, though.
After a pause, the lid closed on the syrup shots, and Wendy resumed.
"Please identify the controller."
"Me!" yelled Kelly.
"Controller identified. Awaiting instructions."
Kelly stared at Gemma. Gemma stared back. Kelly cleared her throat.
"Uh... where are we?"
"This is the RIBRUNT laboratory."
"What's RIBRUNT?"
"RIBRUNT stands for Research Into Biological Reprogramming Using Nano-Technology. It's an experimental program."
"Cooool. And you're WENDY, yeah? What does that stand for?"
"Nothing. It's just Wendy."
Kelly uttered a noncommittal noise of disappointment. Gemma took her turn to speak up.
"Nano-technology? Is that what was in those shots?"
"Indeed. Your bodies now contain a fleet of nanobots, waiting on the controller's command."
Gemma stared, open-mouthed. This was... big. This was terrifyingly big. They should leave right now.
"Give us bigger tits!" hollered Kelly, who clearly had other plans.
"Command received. Implementing changes."
In an instant, both girls felt their clothes grow uncomfortably tight as their breasts expanded a couple of cup sizes. Looking down, they gasped in amazement at the change. Their push-up bras left nowhere for their now-ample breasts to go, but up, and they spilled out of the top of their clothes luxuriously. Kelly wasted no time in relieving her discomfort by removing her top and her bra, and flinging them into a dark corner of the lab.
"Fuckin' 'ell, Gemma, look at these babies! They're gorgeous!"
Kelly cupped her hands under her breasts and gave them a small squeeze. Gemma looked on, conflicted, on the one hand impressed by the transformation, but also knowing about Kelly's capacity to get the two of them in trouble when they were drunk.
"Come on Gemma, take your top off too!"
"No, I don't think I should."
"Awwww, come on."
"No, we should really leave now."
Kelly sighed with exasperation. If Gemma wasn't going to take her top off willingly, then she'd have to force her to play along.
"Wendy, make Gemma's tits bigger again."
"Command received. Implementing changes."
Gemma screeched as her breasts grew another two cup sizes, and her clothes became even more uncomfortable. The seams on her top started to split under the pressure. Kelly watched for a few seconds to see if Gemma would take her top off now. But Gemma made no move to, and Kelly reissued the command.
"More. Make her boobs bigger."
"Implementing changes."
Gemma's breasts grew once more. The seams on her top pulled a little further apart, they were barely holding together any more.
"No, no, stop this!" Gemma protested.
"Will you take your top off?"
Gemma thought for a second. "No, come on Kelly, this is stupid, you've got to stop!"
"Wendy, again. Bigger tits for Gemma."
"Command acknowledged. Changes initiated."
Gemma yelped as her top finally yielded to the immensity of her breasts and ripped asunder. Kelly looked on proudly at her work. Gemma stood before her, her enormous breasts perched on top of a tiny-looking push-up bra, the shreds of her top draped around her shoulders. Seeing her best friend stood in front of her with this magnificent new bust stirred a strange feeling of arousal in Kelly. She'd never been attracted to her before – never really been attracted to women at all – but something was different here. Maybe it was the drink, maybe it was some side-effect of the nanobots, or maybe it was the way she'd watched Gemma's breasts grow and burst out of her clothes, at her command. But she couldn't take her eyes off of them.
"Oh Gemma, your boobs are amazing. They're bigger than your head! I just want to slide my dick between them and fuck them."
"Uh, Kelly... you don't have a dick."
Kelly looked down her body. Gemma was right – she didn't have a dick. Where had the words come from? They'd just sort of tumbled out of her mouth, unbidden.
"Wendy..." said Kelly.
Gemma stared into Kelly's eyes.
"No... that's crazy. I know what you're going to say, Kelly. Don't do it."
"Wendy, I want a dick."
"Command received. Implementing changes."
Kelly felt something shift in the front of her skirt. Reaching down, she lifted the hem at the front, revealing to Gemma the front of her exiguous thong. And indeed, out of the top poked a new growth, 6 inches long flaccid but quickly hardening.
"No, Kelly, this is mad. Stop it now."
Gemma was babbling now, protesting non-stop.
"Oh for god's sake Gemma, shut up. Wendy, can you make Gemma shut up?"
Mid-sentence, Gemma was suddenly cut off. Her mouth continued to move, but no words came out. As the realisation of this sunk in, her eyes opened wide in fear. Kelly smiled a devilish smile, and began to advance upon Gemma's mute body, her erect cock in her hand.
"That's better. Now, this is just going to get lost between those huge breasts. Wendy, make it bigger."