I made this story when I was thinking about how good voodoo inflation was, so I tried making one.
Everett the Polar Bear belongs to me, Kathens the dragon belongs to Kathie.

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Kathens the dragon and Everett the polar bear were in their apartment’s bedroom. Both of them were minding their own business: Kathens was browsing the internet on his desk while Everett was watching videos on his phone on his bed. Bored, Kathens tried to look for something to discuss with Everett. He then spotted a balloon shaped like his flatmate on his desk. “Hey, Everett, that balloon looks good. Where did you get it?” asked Kathens, pointing to said balloon while walking towards Everett’s desk. “Oh, that?” Everett answered. “I got it from a balloon vendor as a gift.” he added. “Oh, okay. Oh, but the balloon looks a little deflated. Let me inflate it for you.” Kathens responded. The balloon had its knot on the navel, Kathens blew some air into the know, hoping it would make the balloon look a bit better. Without Kathens knowing, Everett’s body started to slowly inflate with every puff of air blown into the balloon. “Hey, Kath?” Everett asked in surprise. “I think I’m inflating.” he continued. “Oh… I think it has something to do with the balloon.” Kathens answered, knowing what happened. Kathens then untied the knot a bit, releasing some air until the balloon returned to its original shape, relieving the pressure from Everett’s actual body. “I think this balloon is a magic balloon.” said Kathens, returning the balloon to his flatmate’s desk. “Yeah.” Everett replied. “Anyway, I just remembered that we have to buy some groceries today. Wanna come?” he continued. “Um… I don’t think I want to today.” answered Kathens. “Oh, well. I’ll be leaving now.” replied Everett, having inserted his wallet and cellphone into his pockets. “Oh, bring me some spicy chips.” said Kathens.

Everett went down to the lobby and updated his to-buy list on his phone while waiting for the taxi he ordered. He then bought all they needed including the spicy chips. After that, decided to call his flatmate on the phone. “Hey, Kathens, do you wanna go get some food with me?” asked Everett. “Sure. What do you want?” replied Kathens. “I’m thinking of this Asian restaurant not far from the supermarket.” Everett answered. “It’s only a 10-minute walk from where I am.” he continued. “Oh, I was thinking we could go eat at the European restaurant instead." responded Kathens. "But it's a 30-minute walk from the supermarket, I have to rent a taxi too." Everett answered. "I think it’s much cheaper if you go to the Asian restaurant.” he answered. Kathens begged but Everett still insisted on his decision before finally hanging up the call.

Still unhappy with Everett’s advice, Kathens decided to play a prank on him. He got the balloon, then went to get his helium tank and to the living room. “Hehe… since you’re so worried about the cost, Everett, how about I turn you into my own helium blimp ride?” said Kathens to himself. He turned on the regulator on the helium tank and *pssh!* The sound of the puff of air leaving the tank can be heard. He then inserted the hose’s nozzle into the balloon’s knot, making another *pssh* sound as the helium entered it. As some helium began to inflate the balloon, Everett's body started to bloat up and feel fuller. "Uh… must be the spicy tuna sandwich I ate earlier," said Everett to himself, noticing what was happening to his body. He decided to ignore it and continued to walk toward the restaurant.

More and more helium continued to enter the balloon as Everett walked toward the restaurant, making his body bloat and bloat even more, now to the size of a giant beach ball. He felt fuller and fuller as the helium kept filling the balloon. Even though Everett still noticed what happened to his body, he continued to ignore it, considering the embarrassment he'd get by farting in a sidewalk full of people. Although the people around him gave him a strange look as they saw a balloon his own size. In the middle of his way to the restaurant, Everett's body started to rise higher and higher, as his body started to become lighter, but Everett still thought it was all the result from the tuna sandwich he ate earlier.

As Kathens kept adding helium into the balloon, Everett continued to fly higher as his body continued to inflate. His body had now reached the size of a bed, where he and his flatmate could sleep together on, while the balloon is about 10 inches wide. His clothes started to feel tighter and tighter, exposing his belly. His belly button had also popped and formed an outie. His legs started inflating and separating and sinking into his inflating body, making him lose control of where he was heading. He also lost his grip with his inflating arms and ended up dropping his groceries. Fortunately, they only landed on the sidewalk, leaving Everett relieved when he saw that.

Everett continued to inflate as he drifted through the city and up to the sky, now being the size of a small house. He tried to flail his sunken arms and legs in an effort to keep heading to his destination, but it was no use as he only moved very very slowly in that direction. His clothes continued to feel tighter, but he was glad that they can fit many sizes. As he drifted to the city, his ballooning body became more and more conspicuous to the citizens. Looking down, Everett became embarrassed, realizing the fact that they saw him as a blimp, some even laughed at him. "Man. I hope I won't be on TV and in the news later." he thought.

Everett then found himself in another predicament. His 25-foot body had become wedged between two buildings, as it was too big to fit through. While wanting freedom from being stuck, Everett also felt happy that he was no longer flying but as Kathens kept inflating the balloon with helium, his body became light enough to fight the two buildings wedging him and he proceeded to fly higher as he continued to inflate. With the inflation still being continued, Everett finally heard a ripping sound coming off his hoodie as it yielded to the pressure from his body. He could only hope that his jeans wouldn't eject its button and unzip as more and more people were able to see him flying around as a blimp.

With the balloon now reaching the size of an exercise ball, Kathens finally stopped inflating it and turned off the helium tank. Everett felt relieved as his body finally stopped inflating as his 50-foot-wide body soared above the city. While the fear of not being able to come back down to the city enveloped him, Everett was also filled with glee as he was able to see his big city from above.
Now, all Kathens needed to do was to wait for his flatmate to drift toward their apartment building. "Hmm… all this inflating has made me tired." Kathens said to himself. "I think I'm going to sit down." he continued. He decided to double-down his prank by sitting on the balloon's belly part, putting pressure on it. At the same time, Everett felt some pressure as if something half his size were pressing on his belly. He moved his arms around as if he wrapped them around his belly, to relieve him from the stomach ache. The citizens below also saw the same thing, a 50-foot polar bear blimp with its belly being pushed inwards mysteriously. The pressure made Everett feel like he needed to relieve some pressure, but he didn’t want to embarrass himself so he tried holding it in. Eventually, Everett had to let all the extra pressure out, making him release a massive fart that can be heard through and smelled by the city. Hearing his gas made Everett felt embarrassed.

As Kathens stopped sitting and letting the balloon float, Everett's belly returned to its original shape and he felt relieved once more. Looking down, Everett saw that his body showed no sign of deflation and realized that what had been happening to him was all Kathens' doing. Everett tried to fly through the city by flailing his sunken arms, to look for his apartment building. Fortunately for him, the wind was on his favor, letting him fly faster there. As he finally reached close to the building, he grabbed to the top of the nearest skyscraper he could find. The clear, blue sky suddenly became darker for Kathens. He looked through the window to check the weather, but the sunlight wasn’t being blocked by a cloud, but by a massive polar bear blimp, trying not to fly even higher. Happily, Kathens tied a long string to the balloon’s knot and held the balloon with his paws. He then went down the elevator to the lobby. Outside the building, Kathens let the helium balloon fly him upwards to Everett. There, he climbed his way to Everett’s back while holding the balloon.

“Kathens, you did this?” asked Everett. “Yep.” Kathens answered. “Since you were so worried about the cost of the taxi rides, I decided to turn you into my free, personal blimp.” he continued. “To the European restaurant we go!” said Kathens, as he pressed the balloon’s belly. The pressure made Everett release another massive gas, launching him to the restaurant as Kathens held onto the polar blimp’s hoodie. When they arrived, Kathens decided to use the balloon again to help him get down to safety. “No worry, Everett. I’ll bring you 2 salmon steaks for the service.” said Kathens as he was getting down.

As Kathens finished eating, he got back on top the polar blimp the same way, returned home the same way, and even got his feet on the ground the same way. Kathens then untied the knot and opened it slowly, making Everett slowly release helium from his round body as he slowly descended back to the ground. While Everett’s body continued to shrink, he tried to maneuver his arms and legs, hoping that he would land near the apartment building once he became fully deflated. When the balloon returned to its original shape, Kathens re-tied the knot and Everett landed on his feet, not far from the apartment building.

“Here you go.” said Kathens to his flatmate, handing a styrofoam box of 2 pieces of salmon steak. As they returned to the apartment, Everett decided to watch his TV while eating his steak. However, Everett’s smiling face blushed red as he saw his inflated body on the TV. He could only cover his face in embarrassment while Kathens laughed at what was on the news.