Title: An Itsy Bitsy Balloon
Fandom: Monster Musume
Characters: Rachnera Arachnera, Suu
Contents: Monster Girl, Slime Girl, Arachne, Bondage, Inflation, Helium Inflation, Breast Inflation, Ass Inflation, Belly Inflation, Full Body Inflation, Balloon Girl
Started: 05/11/2018
Finished: 06/11/2018
Co-Authored With: SuccubiOfLust

Rachnera sighed as she nipped the opening of a red balloon and turned the wheel atop the helium canister, stopping the flow, and proceeded to knot the base of the balloon before binding it with a line of thread and letting it float to the ceiling. Her H-cup breasts glistening with a thin layer of sweat bound in a black halter top exposing her cleavage and her waist with a gold and slightly-frilly white trim, she brushed back her lavender hair, exposing her six monochromatic red eyes.

The young Arachne glanced off to the side to see the ever curious transparent blue slime with green tentacle-like 'hair' with three curved yellow tips, wearing her usual yellow raincoat and boots, her small near flat breasts peeking out beneath her coat.

"Don't you touch anything…I'm gonna go get a drink…" Rachnera said in a stern tone, pointing at the small slime with a long sharp, black finger, before turning her back on the slime and pushing the door to her room open and heading out into the hall way, a sour burning scent filling the air, she shivered. 'Miia's cooking…well I hope Honey enjoys his party this might be his last birthday.' She set off down the hallway, the door closing behind her.

Suu looked around the room with her usual small smile, growing slightly when she watched the red balloon bounce off the ceiling and collide softly with the other balloons. Her gaze moved down to the helium canister and she tilted her head to one side curiously.

She moved forward and caressed the canister with her tentacle-like hair, tracing her appendages over it. She inched her face closer and looked into the nozzle, it was too dark to see anything. She frowned, her tentacle stroked the valve atop of the canister; feeling its shape; it turned.

A sudden gust of cold helium struck Suu's eye, she squeaked slightly and pulled back. A sudden wave of panic and concern bubbled inside her as she still felt the helium escaping, she pressed her lips to the nozzle to try and stop the helium from escaping; she tried turning the wheel again to stop the flow, the pressure intensified.

Regret began to fill Suu's core as her breasts began to fill and swell with the helium, the small breasts growing to the size of grapefruits, then a football (1)then a beach ball, growing lighter and lighter as they swelled in size. Her pale blue feet lifted off the floor, sliding out of her boots as she found herself lying on air, barely stopping herself from joining the balloons on the ceiling by her mouth still latched on the nozzle of the canister.

With her new position the helium began to head towards her flat ass, her cheeks starting to swell like a small pair of balloons pressed against each other, slowly lifting the raincoat off her back at her ass swelled. A new sensation began to fill the young slime as her ass lightly tingled and she smiled around the nozzle as she found herself feeling hyper and bubbly, light on her feet, and lightheaded.

Her body floated into a new position, her ass cheeks swelling to the size of watermelons and lifting her until her soles faced towards the ceiling. Her eyes closed and she felt her abdomen start to bulge slightly. Rapidly her stomach swelled as it filled with helium bouncing off her breasts as it reached the size of a beach ball, she bubbled as she felt her thighs start to shrink into her inflating belly as it filled with helium, by the time it reached the size of a small space hopper her knees were sinking into the gooey balloon.

Her tits and ass cheeks began to so sink into her belly, merging into a giant bulbous shape, her arms and legs sinking into her belly as the helium forced her body to reform to accommodate the pressure, her body becoming less defined.

CLANG-CLANG

The helium canister rocked and lightly lifted off the floor before tapping back down as it began to run low on its contents and Suu's small hands and feet began to slowly sink into her body. Her body became fully round, almost smooth to the touch aside from her tentacle like hair barley sticking out above her sunken head.

TAP-TAP

TAP-TAP

TAP-TAP

TAP-TAP

The door opened and Rachnera stepped into the room, a glass of water already half empty in her hand, she paused when she entered the room and sighed.

"I thought I told you not to…" Her voice drifted off as her exasperated expression lit up with her signature cunning smirk. She approached the inflated slime and pinched her lips and pulled them away from the nozzle, chuckling slightly when she saw that the canister was empty, the Arachne then proceeded to tie Suu's lips and bind her thread round her centre tentacle before letting her go, following the slime with her scarlet eyes as she floated up to the ceiling and bounced off several balloons, her rain coat falling from her body, no longer held in place by her arms.

"You make a lovely balloon Suu, I know Honey will love you." Rachnera laughed as she admired the new 'balloon', hoping Honey will like her itsy bitsy addition to the decoration.

A/N Hope you all liked the chapter, please review.

(1) Soccer Ball for my American readers.