“C’moooon, go ahead and have another one!” Yet again, Marie found herself at the focal point of her ditzy cousin’s goading. As the two stunning squid idols made their way through the streets of Inkopolis, Callie made yet another offer to Marie, dangling a sparkling, brightly-decorated can of soda in front of her. When Callie had first taken up a sponsorship deal with the “Big B” soft drink brand, Marie had been fairly supportive of her. From what she had learned, the soda was already becoming very popular throughout Inkopolis, and the Squid Sisters’ public promotion of it was sure to help them stay as fresh as ever. However, as time wore on, Marie had noticed that Callie’s endorsement of the soda had quickly turned into more of an obsession. She was drinking it more and more frequently, even outside of advertising, and was constantly offering more to Marie, as well. While she knew her cousin to be overeager at times, Marie was skeptical that Callie simply liked the soda that much, especially considering the… other effects it was having on them. “Uhh, no thanks, I’m waiting until we actually start selling it,” Marie said, waving aside Callie’s offer. Callie shrugged, cracking open the can herself without hesitation. “More for me, then! Tee-hee~” Callie giggled to herself, before chugging away at the can of soda. Marie glanced over at the bulbous behind of her cousin, watching as it swelled slightly more with each gulp Callie consumed. This was the source of much of Marie’s hesitation. By now, it had become obvious that the soda had the effect of making their asses swell tremendously, and now their once slender lower halves had ballooned out into a pair of gigantic, perpetually-jiggling bubble butts. The growth had been subtle, at first. Marie had noticed Callie’s figure becoming slightly more curvaceous after she took the sponsorship. From there, however, things rapidly spiraled out of control. Callie’s colossal cheeks seemed to grow twice as big every single day, and once she roped Marie into her advertising deals, the same was true of her, as well. Marie tried to limit the amount of soda she drank, but that was easier said than done. Not only was it delicious, it was strangely addictive, as well. Maybe that was why Callie had become so focused on promoting it… “Hey, how long until our contract with the soda company is finished?” Marie asked as soon as Callie finished off the can. “Hmm? Oh, I don’t know, but I’ll be sure to renew it when the time comes.” “Renew it?!” Marie said, gasping. “Yeah! I mean, they just gave us these oh-so-fresh pairs of panties, how could we say no to them?” Callie gave her enormous, bubbly behind a few firm pats, drawing attention to the pair of white panties stretched around it. They were custom-made gifts from the soda brand, emblazoned with their logo, and although they had been designed to fit the excessive proportions of the Squid Sisters, it seemed that their growing rumps were really putting them to the test. Marie had only put hers on this morning, and they already felt too tight. “Callie, I feel like you’re getting too carried away with this whole thing. Haven’t you seen how huge that soda has been making our butts? If they get any bigger…” Marie said, staring worriedly at the sides of her own immense donk. The fact that she could see the swells of her ass cheeks by just looking to her side still astonished her. It was that huge. “Pfff, you’re just getting worried over nothing! Everyone loves our new looks, haven’t you checked our ratings? We’re the hottest girls in all of Inkopolis, and we’re only gonna get hotter and more popular as our booties get bigger and bigger~” Callie said happily, giving her ass an excited wiggle. The slightest movement of her hips caused her bulbous balloon cheeks to bounce back and forth hypnotically, adding to the already copious amount of jiggling they did just from her walking around. “Besides, I know you love this just as much as our fans, hehe…” “Ehhh? What makes you say that?” Marie asked, blushing deeply. With a sly smirk, Callie sauntered closer to her, bumping her ass against Marie’s. Her comparatively larger cheeks created massive wobbles in Marie’s bubble butt, nearly causing her to fall over. “Don’t think I haven’t heard you ‘splatting’ yourself in private, ever since your butt started to grow. Having a booty this big turns you on a lot, doesn’t it, Marie~?” Callie teased in a sensual voice, making Marie blush even harder. “Don’t you want to grow even bigger, show everyone else in this city what a big star you are, hmm~?” Her relentless teasing made Marie’s hands drift towards her privates. Even though they were out in public, the constant movements of her ass, coupled with all the stares it was attracting, were making her very horny. It was undeniable that the same was true of Callie, as well, even if her bubbly personality otherwise masked it. “Nnn… l-let’s just get to the pop-up first, okay?” Marie reasoned. With a knowing giggle, Callie withdrew and gave her back her personal space. The two of them carried on walking, and their gigantic bubble asses carried on wobbling and clapping, the new hallmarks of Inkopolis’ hottest celebrities. As part of their contract with Big B, Callie and Marie had agreed to staff a brand pop-up location in the middle of Inkopolis. Stocked with plenty of soda and merchandise, it was an opportunity to not only promote the brand, but also to promote their own image as an idol duo. By the time they got the location, they found that it had already been set up, and that there was already a crowd of eager Inklings and Octolings standing near, eager to meet the idols. The size of the crowds made Marie a bit nervous, at first, but once they made their way to the stand, gave a flashy introduction, and began doing the sales, their natural charisma easily handled things. Most of the fans there were visiting mainly for a chance to meet the idols in person, but plenty of them seemed to be interested in the soda, as well. More specifically, they were interested in what the soda had been doing to them. “Drinking Big B soda turned both of us into the biggest stars in the city. If you want to look like us, you should start drinking it, too.” Marie said one of several per-memorized sales pitches with as much enthusiasm as she could muster. It seemed to work, as the female Inkling standing before her was beaming with excitement. “Oooh wow, I wanna have a body just like yours, Marie!” she said, grinning. “Hey Marie, don’t forget to drink the soda!” Callie called, taking a break from her selling to bark orders at her cousin. “Do I have to do that every single time?” Marie asked, wincing as she eyed the can she was already holding. Taking another sip would make it the 11th can she had finished off today, and they still had more than a half hour left at the pop-up sale event. She was feeling so full already… “Yeah, that was in the contract, remember?” Callie responded. Marie sighed, feeling her belly grumble wearily at the thought of drinking even more. Nevertheless, she put the can to her lips, downing a few sips for the fan before smiling and flashing a thumbs-up. “Sold! I’ll take 10!” the fan said. Marie quickly exchanged cans for cash, rubbing her aching belly. That last sip seemed like it had been just a step too far for her body. Not only did her ass feel even bigger and fuller, but that fullness had also started to spread to the rest of her body, and it was still intensifying. Even though she wasn’t drinking anything, Marie could feel an uncomfortable pressure continuing to well up in her body, focused especially in her stomach. Looking down, she swore she saw a protruding bump on her once petite torso. Was her belly getting bigger now, too? “Ugh, I don’t feel so good…” Marie groaned, clutching her stomach as it gurgled, the fullness getting even more pronounced. “C-Callie, I think I drank too much of this stuff. I’m so bloated…” “Hmm? What are you talking about?” Callie asked, almost sounding astonished. She turned to face Marie, swinging her gargantuan behind towards the crowd of fans, who openly gasped and gawked at the pair of overinflated panty-clad booty balloons. When Marie looked at Callie, she was horrified to see the same thing happening to her, at an even faster clip. “Look, your belly is growing too!” Marie yelled, pointing. “What? No it isn’t! I would be able to tell if it was-” As Callie said this, she glanced down at her belly, her speech halting as soon as she saw it blimping out right in front of her. “...growing?” “I-I just keep getting fuller and fuller… what’s happening to us?!” Marie said, her voice sounding more panicked by the minute. Both of their bellies continued to balloon bigger and bigger, bulging out from the fronts of their outfits and becoming just as rotund as their ass cheeks. “Haha, d-don’t worry, everyone! This is just another great effect of Big B soda! It gives you a feeling of fullness like no other, which… uh…” Callie stared at her own swelling stomach with a forced smile, her mind racing to come up with a good explanation for something that was very much off-script. “They’re probably gonna stop growing soon… right?” she whispered to Marie, trying to reassure her. In response, Marie could only clutch her belly and let out a deep groan. “Oooh…” BWOOOOOMP! In an instant, the steady swelling of Marie’s belly gave way to a sudden explosive surge of growth, her abdomen rapidly bloating into a massive, taut sphere that easily dwarfed both of her ass cheeks. Callie was only able to gasp in shock before she felt an intense pressure well up in her own tummy, and then… BWOOOOOMP! With both of the idols’ bellies now puffed out into colossal, swelling spheres, the crowd of fans surrounding them began to scatter. Everyone ran off in different directions as they fled from the soda-binging Squid Sisters that looked primed to pop at any moment. Both Callie and Marie certainly felt like they were going to pop, but even as the pressure in their bodies grew more and more intense, their growth didn’t relent. Instead, it only seemed to be getting faster. “A-Aah, the soda isn’t supposed to do this!” Callie moaned. As her belly continued to balloon out in front of her, she felt her already immense ass behind her begin swelling rapidly, as well. Soon, she found herself getting sandwiched by her inflating body on both sides. “I told you this was getting out of hand! That soda is turning us into balloons!” Marie whined, also feeling herself getting smothered by her own swelling body. Their bloating bellies knocked over carefully-stacked displays of soda and standees, while their ballooning bubble butts demolished the back of the pop-up location. By then, the crowds had dispersed completely, giving Callie and Marie plenty of room to get bigger, and bigger, and bigger… “I’m sorry! I couldn’t help myself, it was just too yummy! I got us both hooked!” Callie’s voice became muffled as her massively inflated tits blocked Marie’s view of her face. This only lasted a brief moment, however, before both of their bodies began to slowly lurch forward. Their flailing legs were lifted off of the ground as they floated up into the air, now completely helpless to stop their rapid growth. The idols’ bellies and butts bounced off of each-other as they went airborne, making both of them squeal with surprise. FWOOOOOOOOOMMMM- Once they were in the air, their inflation only became more intense. The pressure in their bodies had become unimaginably intense. Every time they thought they couldn’t grow any more, that they were finally going to burst, their bellies, boobs, and booty cheeks merely rumbled and swelled out even bigger. Strangely, the inflation had gone from being uncomfortable to being extremely orgasmic. Even as she was panicking, Marie couldn’t help but moan and whimper as all the bouncing and swelling made her more and more horny… “Aaah, w-why is this turning me on? I shouldn’t be getting horny from turning into a big, fat blimp, but… it feels so good!” Marie moaned, gritting her pointy teeth as she felt an orgasm shoot through every inch of her blimp-like curvy body, which was now as big as an entire city block. Instead of providing any relief, this orgasm merely made her even hornier, and made her body feel even tighter. The pressure had spread to every limb and curve of her once lithe idol body, making her hands, feet, and face sink into her enormous puffy mounds. Now, she felt it spreading to a specific part of her face, as well. “H-Huh?!” Marie gasped, feeling a sudden fullness in her mouth. Just a few seconds later, she saw what was causing it. At the bottom of her vision was a plump, bright green mass, rapidly growing bigger and fuller. When she tried to speak again, she figured out exactly what it was. “Mmmf! M-My lipfff! Dere growim!” she said, her voice muffled by the immensity of her own inflating lips. As her upper lip eclipsed more and more of her vision, Marie strained herself to take one last glance at her cousin, who was floating directly in front of her. “Mmm cummimmm! Mmm cummimmm!” Callie moaned through her own overinflated pink lips, her cries of pleasure muffled further and further as her pillowy kissers grew bigger than her entire face, completely blocking it. At the same time, Marie’s lips swelled beyond the size of her face, blocking her own vision. She couldn’t see anything besides a puffy, swollen wall of green, but she could still feel everything. Her body still rumbling, trembling with even more pressure and growth as it tried to get even rounder, even fuller, even bigger. She couldn’t do anything besides moan and cum, so she did. Over, and over, and over, and over… Residents of Inkopolis scattered into the city streets to gaze in shock and confusion at the two pasty, growing blimps that now adorned the skyline. Despite their incredible size, the panties both Callie and Marie had adorned still fit as snugly as ever around their booties, giving everyone on the ground a clear view of the soda logo. In a way, the Big B promotion had worked out perfectly, for all parties involved. The soda company had gained advertising that nobody in Inkopolis could miss, and Callie and Marie were now, without a doubt, the biggest idols around.