You were ecstatic as you were about to begin testing on your latest potion you'd developed, and on your favorite test subject Sylveon no less. Nicholas, your Sylveon, had been your partner for several years now, but around 6 months ago everything changed when you developed a special potion meant to make Sylveon stronger. The potion was, innocently enough, only supposed to behave like a super vitamin, but the actual result was far more explosive as Nick had gained about 30 lbs of muscle and a foot of height. This had excited both you and Nicholas quite a bit, and started you on the rabbit hole you currently tumbled down.
Knowing full well that if someone discovered the effectiveness of your potion you would be questioned and your Sylveon tested on you'd decided to live the life of a recluse. After a month the loneliness had started gnawing away at you prompting you to begin work on a potion that would help make Nick a more conversive partner. Two months more of your mad science had produced a solution that was meant to make Nicholas capable of basic speech, but after he'd taken it he was overcome by pain for nearly a week. Wracked with regret you were only able to alleviate the pain rather than cure it until one morning your bulky partner was replaced by a 5 foot tall anthropomorphic version of himself. This had again been a welcome surprise to both of you as now your pet had become more like your roommate.
In recent months though the situation was beginning to haunt your dreams as you'd been becoming more and more attracted to Nick, with his muscled frame and a penis that dangled half way down his thigh, though you'd never let on in front of him. These thought's though had been your inspiration for your latest potion, the one you'd just finished crafting, which would again increase Nick's size and indulge your perverse fantasy of living with a massive 7 foot nudist. Putting the finishing touches on you stood and stretched, eager to see the results.
"Hey Nicky," you called out, using the nickname he seemed to simultaneously loathe and love, "I've got a new potion to test."
Nicholas promptly came bounding in eager to try a new potion, knowing how the last two had benefited him. "Cool! What's this one do Andy?" he asked, unconsciously wagging his tail and beginning to chub up.
"It's a surprise," you told him, trying to play it coy and ignore his rising pink and blue organ "but first I...uh I have to use the bathroom," you left to calm down a little and try regaining control.
As you headed to the restroom Nick began impatiently eyeing the potion on the desk, impatient and eager to see what this new concoction did.
When you returned after splashing water in your face, discovering you actually had had to pee, you found Nick alone where you'd left him with a now empty beaker and your heart skipped a beat. It'd taken only a few drops to make an Oran berry the size of a Wooloo when you'd been testing, and you definitely had not intended to give him the whole thing.
"So what does it do?" Nick asked again letting out a small burp, completely oblivious to what he'd just done.
"Well it's uhh... " you drifted off trying to figure out what might actually happen and how best to explain it.
"Come on tell me Andy!" Nick pressed impatiently.
"Well it...it's supposed to make you...bigger..." you admitted.
"Oh that's so cool! How's it gonna work?" Nick excitedly pestered.
"Well that's the problem Nicky, I'm not sure..." you confessed as a concerned look of bewilderment overtook the Sylveon, "Oh no don't worry I'm here to make sure everything goes ok, I just wish you wouldn't have jumped the gun."
"Good!" the smile returned to Nick's face before his ADD got the better of him and he wondered off to the next exciting stimuli.
You hoped it'd all turn out alright, for now all you could do was monitor and react.