Downtown
An odd pair they were, Dustin and Ember. Not in looks - he, with a perpetual tan and sun-bleached hair, and she with an olive complexion and a head of fluffy russet - but most everything else. Neither were much on shirts, with him in an open front hoodie and her a fur-collared bomber jacket that, despite being left unzipped, managed to move in such a way that indecent exposure was almost never an issue. Nor on pants, with him in tight diving shorts and her her in denim cut-offs. Not at all dangerous by nature - very friendly, in fact - but odd just the same.
The day found them downtown, where in their meanderings a building across the street caught their eye. It was a tall monolith of glass and steel, unremarkable save for how reflective it was in a sea of towering stone.
"It feels like a giant mirror here," Ember said, "doesn't it?"
Dustin nodded. "Explains why vendors don't stand outside during the summer."
Her eyes went between both their reflections, gauging their heights. "Who do you think is taller, you or me?"
He merely gave her a knowing look before arching his back and taking a long, deep breath. His chest rose, then continued to rise as his abs went from flat to to a rising dome. The hoodie parted as his pecs grew, and the hem of his shorts was stretched by the curve of his gut. Just as his midsection neared the size of a beach ball he stopped, plunging one thumb into his mouth and blowing. His cheeks reddened as they swelled up, and a second later a creak, low in volume but getting louder, could be heard coming from him. As the sound rose to a volume disconcerting to passers-by his body suddenly shot outward in all directions, every bit of him turning plumper and quite a few inches taller. He blew out the remaining breath and gasped, looking at their reflections again before turning to Ember. "Me," Dustin replied, beaming.
Ember smiled and gave a playful roll of her eyes before opening her mouth wide and breathing in a huff of air; as she did, her chest jumped up several sizes. Again, and they grew several sizes more, cresting and surpassing basketballs as her stomach bulged with them. One more and they emerged from her jacket, a trio of orbs wobbling in front of her. She moved one hand over the top of her breasts, putting her thumb into her mouth and blowing just as Dustin did. As with him, her cheeks grew and her body creaked, growing louder before she simply surged in size, thicker and higher, standing on par with him once more. "Are you sure?" she asked.
Taking another draw of breath, Dustin blew into his thumb again. The growth came more readily this time, his body letting out a pneumatic groan but offering little in the way of resistance as he rose two more heads in height. It was brief but dramatic, leaving him with stocky limbs and a barrel-chested figure, the curves and contours of his body managing to be both smooth and exaggerated. "Seems like it."
She lifted her hand. "Really."
So it began, each filling themselves with air, growing bigger and rounder than the other in turn. Their taut skin turned smooth as the yards went by, rubbery noises coming from each of them. Whenever one grew into the space of the other the first playfully hip-checked them aside, generating a hollow "bwong" every few seconds that grew louder, deeper, and more resonant each time. Several times they stumbled into nearby buildings or stepped onto cars, but despite their size they caused no damage, bodies stretching as structures and objects sank harmlessly into them. Had any passers-by been near they would have suffered no harm as well, but most people know well enough to not loiter around a giant and giantess in mid-growth.
Soon one halted mid-blow, stopping a few feet shy of the roof, and the other grew just enough to meet them. They were somewhat similar in shape - round, with pronounced chests and limbs that seemed almost too wide and bloated to be bent as effortlessly as they were. Their hoodie and jacket had an improbable degree of give to them, though both were much tighter and neither was able to cover either of their chests.
"We probably shouldn't outgrow our mirror," Ember said.
"You mean like how you outgrew your shorts?" Dustin pointed to one side towards what looked like a discarded denim tent.
"They were on sale. You can probably guess why." She looked down towards his waist; underneath the lower hemisphere of his gut, she could see that one part of Dustin was certainly holding its fair share of air. "Yours are holding on fairly well."
"I don't know," he said coyly, "it feels like they could fall apart at any moment."
Ember simply hooked one plump finger into the hem and gave them a gentle tug, causing every seam to rip simultaneously and fall away. "Oh well," she shrugged.
He shrugged. "Oh well."
Ember promptly hopped into the air as Dustin caught her, pressing her back-first against the building as he drove himself into her, pistoning in and out with a cacophony of squeaks. Each held on to the other as best they could, their bodies pulsing with every breath, their sweat giving their skin a rubbery sheen in the sunlight. Windows rattled from the movement and fogged from the heat as the two human parade balloons fucked in full view of downtown, uncaring of anything but the other's touch.
Dustin felt his balls swell beneath him, and the squeaking sped up as his thrusting grew more frantic, a torrent of gas shooting into Ember as he came. As he did he felt himself deflate, Ember growing larger in his grasp. In response she took his head in both hands, pulling him close and kissing him deeply before blowing into him, returning the air he had lost.
She grinned as she bobbed up and down on him, spurring him to continue. "Don't worry," she said. "I won't let you get -drained- until our fun is over."
*****
Inside the office, one employee wearily rubbed his eyes, trying in vain to blot out the rhythmic thudding and creaking and ignore how his entire window was covered up by one-half of a single, massively inflated ass cheek. Slamming his laptop shut, he stormed out of the office, heading for the relative quiet of the restroom. Some days it was just impossible to get any work done.