Melty Mercury in Outer Space: Chapter 17

Author's note: this chapter takes place after the Tingly Feelings commission which you can read here.

EDIT: Chapter's complete! This was initially a request by whiteglint which I turned into a gift, though the timing of it got away from me. Thanks for your support!

Summary: Nikki is taken over by an extraterrestrial symbiote that changes her into a metal slime girl. While this comes with great power, she's unsure if she can control herself, or handle the extra baggage that comes with it.

[Story Listing]

[First Chapter]

[Previous Chapter]

---

It had been a week since Nikki had spent an intimate afternoon with Brad. In that time, she took to experimenting with her new, alien form, trying to find not just the limitations of her form, but how she could effectively circumvent them.

Earlier she had made a major breakthrough the other day, pacifying an entire half of her mass in her bathroom's tub with a portable speaker connected to a playlist. She could keep that going for hours on end, and only really needed to reintegrate with her extra mass during an awkward connection buffer. She appreciated the extra convenience in getting around without two hundred extra pounds of mercurial ooze attached to her like a needy child.

She even managed to cordone the half of her ooze that still sheltered a small population of Brad's sperm to the bathtub, which really was a relief; Nikki had to go a week feeling their wriggling little tails in her body the entire time, and she got almost nothing done. It left her so hot and bothered... but now she could push that thought aside and turn to more important matters.

Like the trick she pulled out on Brad was something she was very interested in exploring more. The one where she split herself into separate copies. It was incredibly hot in the heat of the moment, splitting into two versions of herself to seduce and bring herself down onto Brad. But it wasn't quite as exciting as that; she was still of one mass, and of one mind, and she only fashioned a separate body for herself—she supposed a 'puppet' would be a more appropriate word—and spoke to herself. It could hardly qualify as a true clone.

But she wondered if she could combine the two tricks somehow; split her mass into different forms, and then have those two masses act distinctly. She wondered if it was a good idea at all; it might be dangerous to let a piece of herself run free, considering what she was already capable of with a functioning human brain. She flirted with the idea—she even ordered a pair of walkie talkies and radios to futz with some experiments—but ultimately turned her attention to more mundane matters.

Namely, Brad's birthday was coming up, and she wanted to do something special for him. The very least she could do is surprise him with a home-made cake; at the very least, she had a lot of the ingredients already lying around. She hadn't assimilated her fridge yet either, which was a small relief. And whatever she was missing, she could just order to have delivered, easy peasy.

There was one major problem she faced. She opened the drawed to where she kept her pots and pans, looking for something suitable for baking a cake.

"...oh."

Empty. The very first night she transformed, she went on a metal-eating food orgy in her kitchen; her pots and pans were the first victims. She grimaced to herself, prodding her fingers together.

"I wonder if Brad would be happy if I just became the perfect all-in-one housewife..." She muttered to herself with a sardonic grin. "...tch, who am I kidding, he knows his way around a kitchen better than I do."

At the very least, she could do a simple vanilla cake. Maybe concepts like layers were out of her depth, and she probably couldn't decorate it like a champ, but a nice, tasty, fluffy cake that would hit the spot... that seemed as good a benchmark as any.

And for a while there, things were going alright! She pulled out a big plastic bowl, prepared the wet ingredients, and fashioned her free hand into a pair of electric hand blenders. She stuck her tongue out as the vibrations rippled her entire body, watching the sugar, butter, and eggs blend into a creamy consistency.

Getting the exact measurements for the dry stuff seemed to come easy to her. She wondered if it had something to do with her eating her scales. She shrugged, incorporating the rest and continuing to beat away until she had a batter good and ready to go!

Everything was coming together; she even had the foresight to order a silicone cake pan, one that was decidedly oven-safe, unappetizing to her, and even came in a cutesy shade of pink! She smiled to herself, feeling really good about how this was turning out so far; the batter smelled great, and she was doing everything to the letter.

"Alright, alright, time to bake this bad boy." Nikki smirked, raising her hand to the oven handle.

The metal oven handle. As soon as her palm settled on the handle, a familiar energy coursed through her.

"Wh-whoa no, shit-" She hissed, her knees buckling; her arm extended heroically to deposit the cake pan on the countertop before her body started to melt and give way entirely. Her body shifted forward on its own, her breasts pressing, smooshing, expanding against the door to the stove.

"Hoo, hoo-" Nikki breath quickened, feeling tendrils of her mass oozing through the cracks, coiling around the red hot irons that glowed within the oven. She winced, her body shlorping in pulsations, her breath shallow as she continued to grow and expand, a hundred oozing tendrils slithering around the stove, leaving a layer of ooze as it crept closer and closer.

Nikki tried to pull her body back, though the effort was decidedly half-hearted; the intense pleasure that washed over her, and the weight of the oven on top of her, weighing down her sensitive regions. Her arms lengthened to hug the massive appliance, rocking it in a cradle.

The bolts that held the oven in place melted away, and the oven jerked forward, screeching against the floor as Nikki's hungry, amorphous body pulled the entire appliance out of the wall, well past halfway integrated with her. Her torso wibble-wobbled to the ceiling before draping over the top, her engorged breast sucking tenderly at an iron burner. She moaned, rocking her hips, urging the rest of her junked appliance to be reduced to so much ooze.

Before long, Nikki raised her head to the ceiling, letting out one last guttural moan as her body enveloped the oven on all sides. Her vaguely cube-shaped lower body extended three feet wide, and was sinking rapidly against the linoleum floor. Her eyelids fluttered open as she winced, her hands pressing against her more pronounced gut.

She felt hot. But the strange tingling sensation had ebbed away. She looked down to her lower body with trepidation. The oven she just ate was huge, relative to everything else she had been consuming...

She gingerly lowered a hand to her gut, finding a seam had formed around her stomach. She curiously traced her fingers around the seam, cradling her naval as she pressed her hand upwards.

"...um??"

The front of her stomach simple opened up; her insides were glowing red, and they radiated heat; her hand ghosted her stomach, feeling a wave of escaping heat.

Her eyebrows furrowed, glancing to the cake pan she had left on the counter. She groaned.

"Ohhhh, my baby baker went and got an upgrade..." She sighed. Her arm elongated for the cake pan, gingerly depositing it inside her stomach, before sliding the door shut. She patted her gut with a beleaguered smile.

At least she didn't have any other trips to make today...

...

...

"Did I get candles for the cake?"

Her head tilted up.

"...shiiiiiiiiiit." She hissed under her breath. She rubbed her apparently-pregnant belly with a grimace. "Gonna be stuck here baking a baby, there's no way I could..."

She trailed off. Her eyes lit up; she cocked her head in the direction of the bathroom. She remembered the bathtub was holding an entire vat of mercurial biomass.

...She cocked her head to the side thoughtfully. Maybe she could take the whole twins theory for a test-drive. Time was of the essence, after all...

She focused inwards as if meditating, whistling to herself as she focused on some internal mechanism. A sort of vibration that welled up from her soul. She focused that energy into a signal, focused it, and projected it.

Her consciousness remained rooted in one place, but an unseen wave bounced off the walls of her apartment, ricocheting around the walls.

Ping.

Her eyes widened. She got a response. And it was close!

She focused her eyes, attempting to bridge the invisible information gap. Sending some part of her elsewhere... to produce a duplicate copy via transmission. It was hard for her to find the words as to what she intended to do, but the process seemed to come naturally to her. It seemed appropriate; she boasted the functionality of a myriad of appliances by now.

Kaclick.

Nikki would've gasped in surprise, hearing the bathroom door clicking open on its own accord. But she already figured her gambit had worked; she had already seen it with her own eyes, after all. She made out footsteps heading in her directions, feeling the vibrations from two different points...

Nikki emerged from the hallway, wearing her hoodie and shorts, the sort of thing she'd bring to university, her skin fleshy and peachy. She glanced to her mercurial counterpart, casually straddling a baking cake in her pronounced gut.

"Hey?" The newcomer Nikki waved.

"Hey." The original blinked.

"I'm gonna head to the store, you need anything?" Nikki gestured to the door.

"Uhhh, not really?" Nikki cocked her head to the side, patting her gut. "I dunno if we need to do this right now, we're basically thinking the same thing..."

"Guess not. Just wanted to give it a shot." Nikki shrugged, pacing right past Nikki. "See you in a few, save some cake for me!"

"Sure thing." Nikki smirked.

They both shot finger guns at each other as the humanesque Nikki exited through the front door. The Nikki that remained behind glanced to her stomach, which remained hot to the touch.

"Okaaay... at least this bad boy won't take too long..." Nikki muttered to herself...

---

While Nikki stayed home to bake a cake, Nikki also opted to make a run to the grocery store to grab some last-minute pick-ups. She was a touch anxious about this entire experiment; she wondered if she could maintain two forms at such a range, but cursory research into short-range radio broadcast signals indicated that a trip to the grocery wouldn't present any major complications. Nikki herself was a technological marvel at this point, and her former smartphone's camera at the very least provided a sort of video feed for the version of her stuck at home.

It'd be an easy trip! Just had to grab some candles. Maybe some extra batteries too. They tended to give Nikki a pleasant little zip during the day. She licked her lips at the thought of it; craving impulse purchases were still a fixture of the grocery experience, even as a weird alien hybrid.

And it was nice to get out of the house once in a while. Nikki was getting more confident, more comfortable in her own skin; she hardly registered her technical nakedness anymore, and getting a feel for a shapeshifted facsimile of her classic, sporty looks felt like a return to form for her. A pair of short shorts, a university hoodie, and a baseball cap to match. Nikki felt a little peckish, but nothing too bad.

Yup, it'd be a nice, easy trip. With no distractions...

"Oh! Nikki! How nice to run into you here!"

Nikki sighed to herself. Of course there'd be a distraction. She put on a polite smile, and turned to the familiar voice.

"Principal Diefen... Walter!" Nikki clapped her hands, remembering herself. "How funny it is seeing you here! ...I-I guess it's not that funny, it's a grocery store."

"Haha, quite." Diefenbaker nodded. "This does save me a spot of trouble; I just wanted to thank you for the bang-up job of staying ahead of the curve for the coming school year."

"Oh, the lesson plan? It's no problem!" Nikki beamed. "I just wrote down what came to me, easy-peasy!~" She admitted sheepishly, rubbing the back of her head. "Now I'm just gearing up for the big open house, haha..."

Nikki was terribly relieved that she could meet up with the principal with her regular proportions. She felt like the older gentleman would've done a double take if he saw the size of the breasts and hips she'd become accustomed to at home.

"Yes, yes, we'll have to make a good impression with the parents and the new students. Those upstarts at Younghart certainly have a vulture-esque disposition, haha... hrm." Diefenbaker adjusted his collar, glancing around as if to check that anyone was eavesdropping.

"Aha, I-I understand." Nikki grimaced with a careful nod. "Oh! I'm bringing Brad this year! He's not faculty or anything, but he's always been curious about it."

"Ah, I heard the stories." Diefenbaker nodded sagely..

"...'Stories'?" Nikki blinked. "Uh, I'm not sure what you mean by that..."

"Oh, nothing heinous! Just a couple of the other teachers mentioning his contributions towards the charity bake sale..." Diefenbaker rubbed his chin.

"A-ah..." Nikki realized what the principal was referring to; Brad was an amateur baker, sure, but when he cooked for a crowd, he didn't half ass it. Even Nikki heard grumbling about the hot-shot upstart producing the highlights of the market; their modest modest looked utterly pedestrian by comparison.

"Well, I was actually in the middle of picking up a couple things for baking myself. Was gonna make a little thing for Bra-a-ad!?"

A pulse of energy washed over Nikki, and she nearly lost her footing, staggering to catch herself on a nearby shelf. Something was happening. To her. She felt like she was being filled.

"N, Nikki? Are you quite alright??" Diefenbaker held his hands out. "Perhaps I could give you a hand with-"

"NO." Nikki blurted. She remembered her tone and forced a smile, unaware that her twintails were writhing slightly on their own. She crossed her legs together and made for self-checkout.

She winced, and closed her eyes. She saw Brad. Naked. Coming down on her. His cock was enormous. Was this happening at home??

Screw check out. She needed to hide. Right now. The bathroom would do, they only fit a single person at a time. She dropped her basket, hobbling over to the bathroom, locked the door, and pressed her back against a far wall.

What are you DOING!?

Brad came early, I had to distract him!

WITH SEX!?

I had to think quickly!

WHAT ABOUT THE CAKE!?

It's already out of the oven! I figured the musk of sex would mask the smell of sugar and-

WE FEEL THE SAME SENSATIONS NUMBNUTS!

No I think Brad's the one with numbnuts right now-ow-ow!!~

Nikki wondered if she was really going crazy, holding an entire conversation with herself. Of course, she had other things to worry about...

Nikki couldn't concentrate, her human veneer fading instantly, her form oozing all over the floor, tendrils lashing as she hugged herself, resisting the urge to moan out loud. Her hand expanded to the size of her head, teasing her throbbing labia; she was climbing up over the walls, attempting to find some relief as her body spilled, rippled over itself, and pounded over and over and over again.

Her twintails were teasing her breasts, each inflating to the size of a basketball; her nipples hardened, spurting the mercurial ooze like a jet, which only dripped to the floor, and reasorbed by the puddle to begin the cycle anew.

Whenever she closed her eyes she saw Brad. Massaging her breasts, biting her neck, squeezing her wherever she pleased, which was basically everywhere. Her breath was hot, her mind frazzled with static; she was cumming over and over in her own pool of ooze, which only reabsorbed through her shapely thighs.

"Gnah!!~" Nikki moaned as her backside absorbed a large metal bar used to help people in wheelchairs get to the toilet. Her ooze trickled between the tiles as she rubbed her back against the wall.

Being fucked two ways at once was overwhelming... This was unbearable. An employee would ask questions. She'd have to abandon mission. She eyed the toilet.

"Oh God, GROSS, they need to clean it!" She retched. Her body lurched forward as a single pillar of ooze towards the sink, dripping down the piping; she'd have to be quick to avoid assimilating the pipes too...

In the end, she failed in her mission to get the crucial birthday candles. She'd need to come up with a backup plan.

She did have that movie theatre app, and she recalled a couple advertisements about how easy it was to book...

The Nikki at home quickly got the memo, and had to think quickly herself. Her eyes flashed and, mid-thrust, she glanced up to Brad while her legs remained spread, and stretched to the far corners of the room like pythons....

"H-hey big guy this is great and all but you wanna go see a movie??" Nikki smiled a strange, tilted smile.

"Huh?" Brad paused, his hands resting on Nikki's pearshaped thighs as her soft body struggled to hold his weight. "...I guess it's been a while, but, uh... right now??"

"Yeah! I heard about this app, you buy movie tickets, skip the line, and scan your digital ticket for paperless entry, plus instantly order food and drink to your VIP Cinemas seat with the new-"

As Nikki rattled off a promotional ad she recalled (and literally downloaded to replay in her head), Brad held his hands up.

"Okay, okay, you sold me!" Brad chuckled. "Just need to get dressed and-"

Nikki shlorped back to her feet, her shimmering oozing skin hugging her curves, unfurling into her usual hoodie-jeans combo in a matter of seconds. She flashed a grin.

"Ready when you are!" She pointed two finger guns, bearing a wide grin.

---

A short car ride to a shopping center later, Nikki and Brad headed to the nearest chain theatre. Nikki was a little cozier than usual, practically hugging his arm.

"Huh, they got little machines now." Brad noted. "Time marches on... it's really been a while since I've been here."

"Yeah, it's all online now! I picked the perfect date flick for us!" Nikki smiled. "Transmorgrifiers!~"

"Oh, I think I know that one." Brad rubbed his chin. "The one about the robots from space coming to Earth to fight off some other robots from space."

"Mmhm! Documentaries really expand the mind!" Nikki tapped her head.

"...I... I don't think it's a documentary." Brad blinked.

"Mm? Well, it is based on a true story..." Nikki tilted her head. "...or, at least, it should be."

"I dunno if I want to live in a space robot warzone..." Brad grimaced.

"Awww, I'll protect you~" Nikki pecked him on the cheek. She casually pressed her palm to the scanner, and the machine pinged, seemingly accepting... something. In the corner of Brad's eye, a QR code had materialized on her palm; it faded away quickly.

He glanced up to the screen. "Oh, movie's starting soon, huh? Lots of open seats..."

"It's pretty much empty! Let's pick three seats near the middle." Nikki leaned over, pressing the prompts; the machine promptly printed out a trio of tickets.

"...three seats?" Brad blinked. "Uh, were you planning on surprising me with a plus one?"

"Ssssssomething like that~" Nikki giggled. "Ooh, here she comes now."

Brad looked up to find a familiar face pacing towards them. A very familiar face. He glanced to the Nikki hanging off of his shoulder... and then towards the Nikki approaching them.

They were perfect twins.

"Aw, c'mon, you copied my outfit too?" One Nikki scoffed. "Well I'm not gonna be the one changing."

"Hey, don't look at me..." The other chimed in, cozying up to Brad. "Sheesh, this is awkward..."

"You planned this the whole time, didn't you..." Brad's eyes narrowed towards the Nikki hanging off his shoulder.

"Ahhh, it'll be dark inside, it won't matter a bit that we're wearing the same thing." Nikki chimed in with a grin.

"Yeah! We just playing up the whole 'identical twins' angle~" The other Nikki clutched Brad's other shoulder, squeezing it possessively.

Brad grimaced; Nikki was deceptively heavy despite her stature, so two of them kinda threw off his balance.

"You girls are playing with fire, y'know that...?" He chuckled, pulling the pair in a little closer. They cackled in unison.

"Ohhhh, you're into it~" The one on the left replied.

"Super into it~" The one on the right added.

The teen at the ticketing booth did a double take at the sight of the identical twin Nikkis hanging off the buff jock-looking dude, but maintained his professional composure, pointing them to the right theatre. There wasn't much consideration for hitting up the lobby concessions; it wasn't like Nikki had a taste for regular food since her assimilation, and Brad took enough dietician courses to understand what exactly went into the popcorn and the various sweets.

To their surprise... the theatre was largely empty. And it remained empty, even during the previews. Brad sat in the middle, flanked by a copy of Nikki on each side, hugging his arms on both sides.

"No fair," Brad frowned. "You claimed both of my arm rests..."

"You snooze, you lose~" Right Nikki cackled.

"We'll pay you back in a way only we can~" Left Nikki insinuated, her voice over a hushed whisper. Neither seemed interested in keeping their intentions a secret... so long as the person operating the projector didn't get smart to their intentions.

Their calves curled around Brad's legs in perfect sync as the theatre dimmed. Their sneakers burbled and melted, pooling along the floor; thin tendrils slipped into the hem of Brad's jeans and trickled up his legs.

"A-ah-" Brad's jaw dropped, the slick feeling coiling up his legs. It settled around his crotch; he could feel a hand clasp his rapidly-hardening cock, trusting back and forth.

Brad leaned back in his chair, fidgeting and trying to get in a more comfortable spot as the various studio logos played out, his sneakers pressing down on the shared pool of mercurial ooze between the twin Nikki's legs. They moaned in unison, their hands squeezing Brad's shoulders as they lustily leaned in.

"Let's make out during the scary parts~" They whispered in unison directly into his ear. They wore conniving grins; just underneath Brad's clothes, the ooze had crept up, massaging his chest, stroking his dick, tickling him all over. The fact that this took place in public was particularly risky... though Nikki loved the element of danger.

"H-how long is this movie?" Brad grinned, rocking his hips.

"Two and a half hours~" Nikki smirked.

"Ohhhhhh Godddddd..." Brad hissed, arcing his neck. "You thought of everything...!"

The two Nikkis chuckled, pecking Brad's flushed cheeks in unison.

"Happy birthday, big guy~"

[Next Chapter]