Life with a sex-crazed Rat companion for Eric was interesting. His former girlfriend turned Rat stuck to him like glue, following him everywhere, half scampering to keep up, never once leaving him out of its sight; including going to the bathroom.
It was overall a rotten, mischievous, and horny thing, happily squeaking garbled demands of "ffuchhk" at Eric even when others were around. It delighted in showing its warped body to anyone it met. Its first interaction with Eric's mother made the woman almost faint, as the Rat bared her dribbling slit at the woman, trailing slime all over the carpet while happily screeching "Rrawt! Raaat!" While pointing at itself proudly.
The woman, horrified, asked Eric what he was doing with such a vile creature, and how to get rid of it. She was dismayed as Eric explained that they would be together for life, and that it lived there now.
The Rat's original family too were shocked when Eric brought home what remained of their daughter, explaining its desire to become a stupid simple animal, all while the Rat lay on its back rubbing its teats and gibbering, "Secks, seeechhks!!! Raaatt! *Squeak*".
It's father was shocked that she'd turned so soon, while its mother was delighted for it, remarking, "She's a proper animal now, good for her! She always did want to be a Rat." Eric managed not to look abashed at how their tinkering had ended up affecting the once Lisa's parents.
It ended up with him inviting Sarah over to his house, resetting her mind back to normal temporarily to get an honest reaction. And it was with the sister that Eric had the longest conversation, talking through how the once human had insisted on becoming a stupid rat, and how it had responded in delight as its humanity had ebbed away.
"How did it even work? How did she turn more into a Rat?" She had asked first, biting her lip. Eric, feeling candid, and curious at Sarah's interest in her sisters devolution, explained that he had a reality altering system that kicked this all off. That he had the ability to give himself transformative cum, and that the then Lisa had insisted on making use of it.
"Oh... So you could use it again to turn her back?" Sarah had concluded. To which Eric corrected her, explaining that these changes were irreversible, no matter what. The Rat was stuck like this forever. "She knew that???" Sarah asked incredulous, to which he nodded.
"Why do you reckon she did it then?" Sarah had asked after a long pause, looking over at her once sister, now fucking itself with a rat dildo almost the same size as itself.
"Rat wanted to feel sexy and happy. And... In a weird way, this was how it had control on its life. Doing this was Rat's choice, no one could make this for it, and once the choice was done, no one could undo it." He answered after a long pause. "...Also, your sister was super kinky..." He added with a wry grin.
"Did... Do you think she enjoyed going as far as she did?" Sarah asked, blushing.
Eric laughed. "Going this far was its own idea. It enjoyed the process immensely. I would have been perfectly fine with the Rat stopping earlier too. In fact we had stopped and I thanked that disgusting vile little thing for going to its then form. It then used what little brainpower it had left to insist on going further. It's on the cusp of just being a rat right now."
Sarah had gone crimson. "That's so fucked..." She whispered. "And... Do you like her like this?"
"Oh yes... That Rat thing is so fucking sexy." He answered, to which Sarah fidgeted and tensed her legs, looking at the rat awkwardly poking itself with the Rat dildos.
"Do you want to check it out?" Eric ventured, watching Sarah try to internalise her interest in the creature. When he got neither a yes or no, only a pained expression of unsureness he proceeded anyway.
"Hey! Rat! Stop that! Come here and show off your disgusting body." He demanded sharply, patting his lap.
The Rat jumped up, ears perked, yowling a happy "Wwrraat! Seeecks!", before scampering over, climbing onto Eric lap, and flipping onto its back. Hind legs resting on Eric's chest, gently clawing needily at his chest with its rat feet. The creature was facing him, trying its best to do a sexy smile, mewling and squeaking, while tugging at two of its black leathery teats.
"Oh god!" Sarah exclaimed. "She reeks of... Of I'm not sure what. But she stinks!" Her nose wrinkled.
"It's pheromones... well, she wasn't called Smelly Rat for nothing..." They both chuckled.
Sarah's eyes roamed all over the creature, fascinated. "God, her tits are so weird looking." She started. "Not tits, duds and teats only. Leathery, long, saggy. They feel amazing to suck." Eric admitted, as the Rat squirmed and yipped, "teeeeeeetss" loudly, while switching her fondling to her lowest set.
"I think it was the growth of her extra teats that really set your sister on the path of becoming a rat. Before it she was quite unsure, but once grown I think she started to see and imagine herself as an animal more. God it took her so long to admit this is what she wanted. Months! But then, once she knew, it happened so fast. I thought she'd need months again to get to here, years even I'd expected. But in the end, she just couldn't resist the floodgates she'd opened, one glimpse of what she would become and she was doomed."
The Rat squeaked in delight at people talking about it, and, using its paws began fingering its mutated cunt. "Haaappyy.. nyahh.. *squeak* Rat-yesssh". It screeched.
A scarlet Sarah fidgeted again, watching her once sister squirming. Legs crossing and uncrossing. "Her... Pussy looks so weird! Her clit..." Sarah trailed off, eyes wide and lingering over the leathery, mottled, swollen slit between her once sisters legs.
Eric scratched his jaw, "well, yeah... That's that a rats pussy looks like. I mean, if it was increased in size to fit a human. And having such a massive clit seems to be a bonus. This disgusting filthy Rat loves playing with its."
Sarah bit her lip, words unspoken. "And she's in constant heat too... That's why she's so wet." He pointed at the line of rat grool dribbling from the rats puffy slit.
"And like... Why? You fuck her? Does it like, feel good?".
"Fuuucchkk. Raaaht. Seeecks. Erreeeck". The Rat squealed happily. Tugging at a fat teat, while also slicking its rat claws into it puffy sopping rat-snatch with a squelch.
Eric smiled hungrily at his Rat companions antics, placing a hand on its furry chest, squeezing a half dozen swollen puffy teats all at once, while the creature creamed itself in delight. "Teeeeats... Ff-fuck-Raahht!" It yipped excitedly.
" Yeah! Fucking it feels really good. Knowing that that was once a super smart, gorgeous girl, that drank so much Rat cum that it mutated into this disgusting creature is super hot...
Don't you think? It told me you used to get a kick out of calling it names and fucked it with a dildo once... Well. Told me before it turned into a dumb animal..."
"N-nyaminmal. Fucchk", the Rat attempted to mimic the last word badly, while thrusting its hip needily at its master.
He looked at the scarlet Sarah and held her gaze as they locked eyes, all the while the Rat humped air, "fuuchkk! Rahhht...!". It babbled.
Eric cracked a smile, "Hot right?!". The was a moments pause, then Sarah's face cracked into a wide grin. "Yeah..." She breathed. "That's hot..." She admitted, chest heaving. Before looking down at the Rat.
"Not the smart sister now are you?" She sneered, grinning. The Rat, oblivious cackled. "Smaaaahrt! Smmarrrt. Raahhtr. Secksss!"
"Just a dumb fucking Rat. A Smelly, fucking animal." She cajoled
"Secckkssyy! Dummm!" The Rat used both of its paws to hold open its dribbling snatch, then pawed with its feet at Eric. "Coocckk!", it begged. The smell of its rat pussy had now completely suffused the room and was affecting both Eric and Sarah.
Eric's cock was straining and tented in his pants, while Sarah's nipples poked from the straining material of her string top.
"Sooo..." Sarah drawled. "We fucking this thing or what?".
"Fuuuckk!" The Rat happily squeaked, a squirt of rat juices splattering onto Eric's top.
And so the two took off their pants, Eric dropping the Rat to the floor momentarily. It crouched, sniffing the fallen clothes articles, making excited yips.
"You can do what you like to it. It'll cum from pretty much anything, and will do anything you ask it." Eric told Sarah as she stood, bottomless, long shirt covering the view to her pussy from above. Her eyes boggled as she viewed him though, eyes glued to Eric's crotch.
"Woah! Fuck! Is that a...?" She started before Eric interrupted. "A rat cock... Yeah!"
"How?" Sarah puzzled, before making a 'duh' motion. "the reality altering 'thingyvac'."
"Chronivac" Eric corrected.
"Yes, Chronivac. I thought it was just rat cum you made, didn't realise it was a rat cock too." She blushed. "So... Are you stuck like that too?". To which Eric shook his head. "Naw, this can be reversed whenever. I haven't been drinking the tainted rat cum. Not like that thing there. " He pointed at Rat on the floor.
"Yummm", it smacked it's lips. "Mooahhr!" It demanded petulantly. Patting its pot belly, and clenching its puffy stained rat snatch, squirting gamey smelling viscous rat grool all over the carpet.
"I see..." Sarah answered, looking down at her once younger sister. "Would she lick me out if you asked her".
Eric gave a half shrug, "Not much that disgusting thing wouldn't do. Rat! Go lick out your sister" he commanded, pointing at Sarah.
Excitedly, the Rat flipped onto all fours, scrambled over to Sarah, then haunched up on two legs to stand before her. Sarah sat down on the bed made eye contact with Eric, and spread her legs. As her tee rode up he saw the snatch of his once girlfriends sister for the first time.
Where Lisa had been shapely, blond, sallow skinned, and a touch below average height; Sarah was ginger with a mop of very curly hair, tall, extremely pale, heavily freckled, and had a plank for a chest. Even her face was very different from her once gorgeous sister, she had a wide mouth and a generous bottom lip, her eyes were big, and her nose a little puggish, upturned. She was unconventional looking. Pretty enough, but definitely not the knockout Lisa had been.
Her snatch too was very unusual, ginger pubes framed a huge clit. A pale freckled hood partly covering a red angry glans. It was so big it almost seemed to have the beginnings of a shaft behind it.
"C-cooock!!!" The Rat screeched excitedly and scrambled with paws and claws to pull itself up onto the bed between Sarah's legs and dove into her snatch, paws clutching her inner thighs.
Sarah closed her eyes for a moment and moaned under the Rats assault. "Hmmmnnn" she purred, eyes fluttering open to look at Eric. He stood with his red rat cock poking proudly from its sheath.
"This Chronivac thing is the best thing ever..." Sarah moaned. "... As are you!" She gasped. Eric started, visibly surprised at the compliment.
"Ye both turned my perfect little sister into the dirty little rat that she always was." Sarah grabbed the back of the rats head and shoved it hard into her pussy.
"Perfect little rat always showing me up, stealing you from me, when I asked her not to..." She growled.
Just then something hit Eric. How he and Lisa had originally met. Lisa was an underclassman, a year lower. He knew Sarah from his class, paired for a science project. Decent enough classmates, but he'd always found her shy and awkward, but working together he had warmed to her well enough. It was through her he'd met Lisa when she'd come up to him, remarking that he was in the project pairing with his sister, and wanted to get his number. She'd immediately shown interest and clung to him. It was around then too that his burgeoning friendship with Sarah seemed to peter out.
"Wait" Eric held up his hands, "you... You like me?". He quizzed.
Sarah stopped moaning for a moment, her mop of curly hair was beginning to plaster to her face with sweat. She licked her lips, then swallowed. The only sound in the room the enthusiastic slurping by the Rat. Eyes hooded she kept eye contact with Eric.
"Yeah... Didn't think you were into weird looking girls when you jumped my perfect sister's bones at the first opportunity. But here we are...". She pointed at the rat.
"Maybe I should have let my bush grow out and showed you my furaffinity page and you'd have fucked me instead of her..." She added.
"You have a furaffinity page?" Eric asked, Sarah nodded. "Yeah... You missed a trick not getting with me first... This shit right here. " She pointed at the Rat that'd once been her sister. "If you wanted Lisa to be a rat, wouldn't have taken months to turn her if you'd gotten with me. This is hot as fuck, like you said. No point in hiding that now."
Eric was blown away, still reeling from the info that Sarah had been interested in him before Lisa, and that Lisa had intentionally gotten with him after being told not to. He didn't know what to make of it. He knew back then that he thought Lisa was by far the hotter sister. But now looking back, there was something very intriguing about Sarah's unusual looks, and he wondered how things would have been if he'd noticed Sarah's interest and gotten with the less obvious choice.
Panting louder and quicker, Sarah seemed to be barreling to an orgasm as she grabbed the Rats face and ground it into her pussy until her face turned red and she grunted her orgasm.
"F-f-fffuck..." She grunted, going back to panting and unceremoniously pushing her sister off her. The wiped mouth with the back of her hand. Meeting Eric's horny eyes she grinned.
"Right..." She said. "So... We going to have fun with your Chronivac so?"
Eric smiled, this was going to be a whole new perverse chapter, "you're not thinking something boring like 'get big tits', or 'curves to die for'?!"
Sarah laughed a hearty laugh. "No... I don't think I need that kind of thinking anymore..." She looked down at the Rat mewling piteously on the ground, curled into a ball, and licking itself out.
"Think you need to fuck your Rat girlfriend... It looks pretty needy." She pointed out.
---
Sarah turned out to be the real devil on Eric's shoulder, and a master information broker. She showed Eric her furaffinity page; which turned out to be a prolific collection of transformation stories, ranging from the reasonably tame, to the absolutely demented. Sarah seemed to use pretty much any animal or transformation, but did seem to have more general domesticated or farm animals than others.
Her first suggestion as a peace offering and show of good will, was that Eric set up the Chronivac so that only he could actually use it. Seeing the merit in that he did so.
She didn't suggest any alterations for herself either that day, more curiously quizzing what the Chronivac was capable of.
"So if we're starting, how about at school, I know a few juicy secrets we could use. The joys of photos on an unsecured cloud". She offered,
They turned out to be;
Kimi, a quiet unassuming girl from their year who apparently fucked her dad on the regular.
Brooke, one of the "bitch" circle, enjoyed sucking off and getting knotted by her dog.
Cal, a popular handsome boy, was in an affair with one of the married younger teachers, and her pregnancy was secretly his.
Amber, a girl a year below even Lisa, and one of the most posh, snooty girls in school, was a little bit "too" obsessed with her horse.
And finally the twins Carmen and Jorge were very much taking after Jamie and Cersei.
All needed some kind of Chronivac adjustment to make them susceptible to mutagenic change, so a blanket 10% drop in their inhibitions was applied. For both Amber and Brooke, Sarah and Eric were happy to let things play out with their animal companions
For Kimi, her father had a solid tit fetish, so his semen production was changed to an unscrubbed bovine variant.
And finally, Cal was given Goat cum, but just for fun the teacher, Kiara, had her lactation changed to milk flavoured goat cum too.
Carmen's grool production and Jorge's balls were both given Rat cum production, a classic in Eric and Sarah's eyes.
Finally finished with their plotting, Sarah put her pants back on, and with a pat on Eric's shoulder, left for home, leaving him wonder... How did he miss her signals all those months ago?