Mermaid Mega-morphosis

Date Written: 

Shelly and Piper kicked off their shoes as they stepped in through the doors of their beach home, with their arms full of shopping bags. Shelly was practically bubbling with excitement at the Spa and High Tea day they were gonna put together for their 3rd year anniversary. Piper was swollen with joy too, but only because she loved her teeny, skinny-mini little girlfriend so much it made her heart hurt. She put her heavy bags down on the table and whilst Shelly was facing the counter, she snuck up behind her and hugged her, lifting her high off the ground, causing her to squeal and giggle. Shelly wriggled in her arms to face her and slipped out and almost headbutt the DD cups that were filling up Piper’s crewneck tee.

“Careful! You don’t want to bruise my weapons of mass seduction before we have our nice bath together!” Piper chuckled, placing a kiss on her forehead.

“Hah! That’s what you get for startling me!” She teased, being squeezed into a tight, cosy hug.

Piper leaned over to whisper in her ear. “Why don’t you get the bath started and I’ll put the shopping away and come join you in a bit?”

“But we haven’t made those mini salmon and cream cheese sandwiches that you like so much.” Shelly Whimpered.

“We can make them together after; I’ve got something to show you…”


Shelly ran them a warm hot bath and added a seaweed and witch hazel bath bomb to the mix. She unbuttoned her autumnal cardigan and slipped out of her sweet, floral dress. She sat on the edge of the bath, wondering whether to wait for Piper to come in, so that she could strip tease her, but when she looked down at her pretty itty teacup B cups in her white, daisy patterned bralette, she didn’t really think they were worth anything to get excited about. Maybe it would be better if I left the strip teasing for the thick amazon babe, she thought. She stripped off and lay down in the sudsy bath.

The door creaked open, and Piper jokily sang “When the shopping’s away, the lovers will play!”

Shelly giggled, before looking at her through her long eyelashes and held out a dark, tanned short leg from the bath. “I’m not gonna let you in until I get a strip tease.”

“Oh, you ask so much of me, mistress…” Piper smiled and looked at her little girlfriend with hooded, bedroom eyes and flicked a tress from her short, blonde curls out of her face.

She unclipped her earring and flicked it into the sink with a ping. She pulled off her grey camouflage jacket as Shelly waited in anticipation. Her tight t-shirt was pulled above her head and her boobs jiggled as she bounced up and down to wriggle it free. She bent down (Giving Shelly an even better angle to ogle her cleavage…) and slowly pulled down and stepped out of her yellow chinos. She stood to show her full, towering, inverted triangle figure, in all it’s glory, in a matching set of silky dark teal lingerie. Which she proceeded to strip off and throw at Shelly’s face! Piper climbed into the crowded corner bath, (Fishing out her soaked knickers) and slid down beside her elfin minx. Shelly scooted up to her and rested her head on her shoulder and was embraced into a hug.

“Do you remember that time you almost drowned?” Piper piped up suddenly.

“That’s a pretty random question to bring up…” Shelly laughed, awkwardly.

“Well… Do you remember telling me about waking up to long blonde hair tickling your nose and seeing a chest covered in pink scales?”

The bathwater started to foam up and whirl around Piper, bubbles began to float in the air. Shelly felt her legs become a bit squashed as Piper’s thighs expanded against her. Piper’s hair grew longer and her body was dappled with glistening, Magenta scales as a ginormous tail fluke emerged from out of the bath water and slapped down onto the bathroom floor below.

Shelly’s mouth hung open.

“Surprise! I’m the mermaid who saved you from drowning all those years ago! Happy Anniversary!” Piper cheered, though her expression seemed nervous.

“But How?” Shelly squealed, looking down the side of the bath at the glorious tailfin.

“You don’t like it?” Piper asked, shyly.

“No, it’s not that… I didn’t even know mermaids existed and how does all this tail fit in your lovely legs?” She stared down at Piper. “And did your already enormous boobs get even bigger?”

“Oh yeah, I shrink them down in my human form; as it turns out, having a big pair of ‘floatation devices’ around your neck is a bit cumbersome on land.”


An awkward pause.


“Can I hold them?” Shelly asked, all red cheeked and coy.

“Go ahead, I just grew a tail but you want to investigate a few more inches?”

“You know me,” She said, cupping the twins. “I’m a boob woman, If I cared about tails, I wouldn’t be a lesbian, you’re scales feel really silky soft by the way.”

“Thanks, I kept them well moisturised.”

“What size are these things?”

“I’m not sure, I never got them measured because Y’know… it’s hard to get to a boutique with no feet.” She said, heaving her heavy tail up and waggling it.

“So, if mermaids can shrink down a size… does that mean they can also grow up a size?” Shelly raised one eyebrow, suggestively.

Piper waggled her brows. “Want to have a little fun?”


Back in the kitchen after drying off and getting changed, Piper (now back to her human self) sat at the dining table in her lilac joggers with matching crop top, while Shelly cut triangle sandwiches on the counter in a fluffy yellow dressing gown, her hair in a wrap.

“So, you need food to change shape?”

“Kind of, I can change without it but…” Piper patted her breasts. “…I going to need the extra mass.”

“I wish I could make my boobs huge.” Shelly moped, bringing the teapot and tray to the table.

“I like your little boobs though; they don’t get in the way when I hug you.” Piper mumbled, her mouth already full. “Now…”

“Wait! Wait! let me get a measuring tape, Let’s see how big your mermaid boobs really are!”

After grabbing what she needed, she perched herself on Piper’s lap and measured her band and cup size.

“You’re about… 38DD as a human, but as a mermaid…”

Shelly sat back on to the table as Piper looked down at her breasts and relaxed with a sigh. Her breasts bulged forward at first, then started to round out, pushed together by the confines of the bra. She filled the sweetheart neckline of her top and it started to creak as she still blossomed even more. Shelly bit her lip with excitement. As the elastic around her chest started to strain, she stopped growing.

“Phew! I’ve been holding these puppies back for years!” She sighed with relief and cupped her bosom.

“Let’s see” Shelly cooed. 

She wriggled with happiness as she perched herself back onto her girlfriend’s thigh and wrapped the tape around her.

“40F!” She squealed with delight.

“Huh… I was a lot smaller that I thought.” She said, giving one a squeeze.

“How big did you think you’d be?”

“At least a G-cup.”

“Well…” Shelly said, with a wink. “Get busy growing.”

“Hold on tight…” Piper chuckled.

Piper held Shelly’s hands against her humongous, swelling boobs. They felt like water balloons, overflowing under a tap. Soft, spongey and weighted, still holding their round shape as they rose up. Shelly gasped as the hem of Piper’s top lifted away from her body. She kept growing still. Piper huffed as the lilac bra squeezed her. Her engorged boobs heaving over the neckline. Shelly let go and backed up to the kitchen table, leaning back away from the straining top, fit to bursting.

“Maybe we should get you out of that top before you pop…” She tensed up.

With a resounding crack, the straps snapped and the sides' seams began to split. Unsupported, gravity pulled her enormous boobs forwards and they landed with a hefty thud on the table.

“Careful sweetie, you’re a bit off balance now!” Shelly cried.

She tried to steady her, heaving up her not-so-fun-anymore-bags from behind.

“Whoa… that’s why I shrink them while on land.” She grunted, rubbing her sore boobs. “Oh jeez! This is hurting my back already…”

“I must say, you do look a bit… out of proportion right now, specially with the wobbling and swaying to keep your balance.” Shelly hummed, concerned and sat back on Piper’s lap to prop up these monster boobs.

“Well, Let’s see if we can do anything about that…” Piper smiled, clearly scheming.

Her thighs and hips abruptly swelled up. It took Shelly by surprise as these new birthing thighs pushed her up just over Piper’s massive shelf of a bust. Her chin just resting above her deep cleavage.

“Oof! All this blowing up like a pufferfish is making me hungry again.” She puffed out a sigh, leaning back in her chair and rubbing her belly.

“Shrink back down to size if you want and I’ll make us some more food.” Shelly said, patting her girlfriend's bouncing chest.

Piper grunted and clenched her body before looking quite troubled.


“What Ooops?”

“They won’t deflate…” She cringed, pushing her inflated bosoms together. “I might have spent up my metamorphosis powers for now…”

“Oh Gosh!” Shelly Gasped. “Would feeding you up some more help?”

“I don’t want to grow any bigger!” She cried; her dark eyes almost as wide as the stretched-out bubbles in her torn up sports bra.

“What if I prick you with a pin?” Shelly panicked.

“Nononono!” Piper said, quickly. “I’m not full of air! It’s Blubber! You’ll just hurt my boobs!”

“Blubber? You mean like a whale?” Shelly question, an eyebrow perched.

“Well I am a marine mammal; it gets cold in the sea.” She shrugged. “My powers just control how much of it my body has, I can only use them so much though; I’ll be right as rain after a nap.”

She shifted in her chair before letting out another sigh. “Ummm…I can’t move. Help.”

The chair screeched across the wooden floor as poor Shelly dragged a heavily fattened up Piper into the bedroom to rest. Her widened girth just barely made it passed the doorframe. After a couple hours of heaving her into bed, unpeeling the dregs of her destroyed bra and tight joggers off of her bloated form and making her a hot water bottle for her back, Shelly managed to get some dinner on the stove.

She made sweet chilli linguine with courgettes and prawns and brought it into the bedroom on a tray. Piper was squashed into a t-shirt that used to fit baggily on her. Her boobs had finally deflated a little but were still stuck out like atomic warheads. She was resting against the headboard, struggling to read a book over her weapons of mass clothes destruction.

“I couldn’t sleep very well; I managed to force them down but can only go to about an H cup…” Piper moaned.

“I’m sorry…” Shelly said, placing the tray on Piper’s lap.

“It’s not your fault, Buttons.” Piper stroked Shelly’s brown bob. “I should have taken it a bit slower, my powers are funny like this…”

She took a bite out of her food and swallowed, before looking shocked for a moment…

“Is there prawns in this?”

“Yes, why?”

Piper gulped. “I’m allergic to prawns.”

“OH GOD! Piper I’m so sorry! Do you need me to call a doctor?” Shelly Squealed.

“No… Mermaids’ Allergies aren’t like that…” Piper begun to breath heavy.

Piper’s face and chest immediately started to turn white and her hair and the tops of her arms turned black. She pushed the plate away, lifted her top and struggled to see her belly. It was white too, with patches of black up the sides. A black and white tail fluke suddenly popped out from under the covers, expanding outwards, about to outgrow the bedframe.

“I mean, we do get a bit of swelling but…”

Her stomach bellowed loudly and begun to puff out. at first it only looked like she had finished the whole plate of pasta, then it started to rise like a bread loaf in an oven, before looking like a huge, overgrown watermelon.

“Long story short I’m turning into a Merwhale, Were-whale, whatever. Now, by the looks of the size of my tail, I’m not gonna turn into a cute little beluga either!” Piper freaked out.

“We’ve got to get you into the water before you outgrow the house!” Shelly screamed.

“Help me up, I’ll try to drag myself out, don’t forget to grease the doors, or I’ll definitely get stuck.” Piper panted.

Shelly pulled at Piper’s hand and tried to heave her up, but her swelling belly refusing to bend forward was making it a difficult task, so instead she tried to roll her like a sausage, but her wide spanning tail kept getting caught. As time was getting away from them, Piper’s waistline kept disappearing. Her tummy moaned again and surged forward; she looked like she’d swallowed an exercise ball.

“It’s no use! We’re gonna have to call the firemen or seaside rescue or something!” Shelly squealed.

“As much as I don’t want the whole world knowing I’m a mermaid, you might be right…” Piper huffed.

Piper’s body was now catching up with the rest of her, her tail, now looking more like a whale’s tail was stretching and bloating out, even as it was crammed against the door. She was turning into a giant; her big bulbous stomach still dominating her frame and her breasts started to balloon up again. This time, completely out of her control! The bed’s legs gave way under her huge weight and dust was starting to fly up as the foundation of the building got wobbly. Shelly begun to sob in fear, Piper’s tail now completely blocked off the exit and both their phones were in the kitchen!

Piper picked up Shelly in her giant hand and put her over her heart and covered her with both hands to protect her from the collapsing ceiling.

“It’ll be alright.” Piper soothed her.

A final swell of growth bust through the walls and rubble piled down on top of them. Lucky for them, it was high tide and getting dark when their house on stilts collapsed under Piper’s exploding girth. She managed to backpaddle out to sea, to hide before anyone saw the 26ft long, voluptuous, pregnant-looking mermaid.

Shelly looked up from hiding under Piper’s hand and found herself in the ocean, sat atop Piper’s colossal mounds as she drifted, effortlessly on her back.

“Are you okay, Button?” Piper asked, sweetly.

“I’m fine, just a bit cold, are you okay? Your poor belly...” Shelly cried, looking at the huge white stomach just bobbing in the waves.

“It’s alright, I only grew to the size of a Minke Whale this time; the first time I had shrimp, I ballooned to about the size of a Humpback whale, warts and all and my tummy and boobs blew up twice as big as this!” Piper laughed. “I’ll start to return to my old self again in a couple days.”

“So shrimp messes with you metamorphic powers, huh?”

“Yeah, funny story: I managed to accidentally eat it during our second date, I was gonna explode out of the sushi restaurant, so that’s why I legged it…”

“Yeah, I do remember that, I didn’t hear back from you for a while and thought you didn’t like me…” Shelly whimpered.

“I could never feel anything but love for you Buttons.” Piper cooed softly, placing a giant finger under her chin. “Besides I couldn’t get to a phone… my big fat butt had expanded to the size of a Pilot Whale and I was beached behind an alleyway feeding off scraps people threw away…”

“I wish you’d told me sooner.” Shelly said, cuddling up to Piper’s Hand.

“Sorry Sweetie, I just needed to be careful, Mermaids have been a strict secret of the ocean for so long, it’s hard to know who to trust it with, but after everything we’ve been through… I think I can trust you to keep it.” Piper smiled and lifted Shelly to her giant lips to give her a kiss.

“Careful! You’ll swallow me!” Shelly laughed.

“It is tempting, I am still hungry…” Piper teased, slapping her great, white stomach.


Under the cover of nightfall, Piper returned Shelly to the safety of the beach. She would be staying at her mother’s, now that the beach house was destroyed. A quick wave goodbye and Piper returned back to the darkened ocean. Shelly shed a tear, on that moonlit beach, her heart hurting for her Mermaid’s safe return.

Author's Note: 

My first attempt at an inflation story! I thought a Human/Mermaid romance would make for a cute story. I hope you like it, maybe we'll see Piper and Shelly again in the future...

Average: 4.2 (5 votes)
Pennsylvania Ki...
Pennsylvania Kite Weather's picture
Playful, delightful, wonderful!

When you replied to one of my comments that I had critiqued your second story, I needed to go searching for the one I missed—and I’m glad I looked! First of all I love mermaids, like, had-to-have-used-one-in-a-story-myself levels of love. Mine had it rough, but I’ll never say no to seeing a creature from the sea getting along well with another human. It’s one of those classic love tales often with a twist or two, because interspecies bonds can be unpredictable.

And that relationship is kind of what sells it for me here the most; the pair’s interactions from the get-go show how deeply they’re there for each other. While Shelly’s attached to her girlfriend’s regular physique, the way she coaxes out and explores those powers heightens that admiration even more—it’s really sweet. (Even the little line how Piper shields Shelley from the roof caving in; it’s lovely that Piper reciprocates things.) It’s especially the demonstration and the physical challenges that Piper winds up revealing about herself throughout these mini-multi-acts which keep things engaging. These abilities even separate them both at the end, which makes me sad, but that’s your success showing at portraying these women; needless to say I’m hooked on this pair and I hope they can reunite and go further with what Shelly knows of her partner now.

Most of all, I enjoy best that the inflation content is equal parts pretty to read and a “vehicle” that moves the story along, getting Piper in bed, sending Piper out to the sea. Your style once again plugs so many great visual metaphors about Piper’s growing curves—now I still feel as though they outnumber other sensory details a bit (like feeling itself; “Soft, spongey and weighted” is really on the right track though!)—there was fortunately a lot of Piper’s commentary mixed in that supplied to readers how it is to be big instead of what it looks like, and I think that helped drive home the realism. 

I’ve gushed enough. Kudos!

Little Bubs
Thanks again!

Thank you again for the comment, Mermaids are some of my favourites too.

You'll be pleased to know, we will be seeing more of Shelly and Piper and plenty more ~*mermaid magic*~ will return with my next story.