Icicle sucked in a breath, his chest tightening, as he felt the tip of the air pump first prod against his ass. Carefully, biting down on his lip, he forced himself to relax. Seconds later, his enthused, winking asshole happily gulped the rubber nozzle down, the pressure of it a gentle echo what Midnight tended to put him through.

Still… He wiggled his toes, and squished his plump ass further against the mattress. The nozzle pushed up into him, firmly lodging itself in his rump. He gave his tight ring a squeeze, and squealed happily as a familiar resistance pushed back. His cock firmly hard and throbbing against his belly, Icicle smiled, turned to the pump, and flicked it on.

There was an instant rush of pressure up and into his middle. Icicle groaned lewdly, cradling his gut with both arms as he felt the tightness in his ass redouble. Then, with gentle awe, he watched as his belly began to bloat out with air, its curves growing rounder, tauter, yet light, pulling him and relaxing him rather than forcing him down. His stomach trembled, each pump of air inside his ass making it swell larger in size, pressing his wiggling cock down and straight. He giggled airily, giving his belly a squeeze, and grinned when it barely even squished.

Already looking like he’d downed a meal fit for a family of four - or else grown pregnant for ten months - Icicle let out a grunt as he felt the pressure begin to flow to other parts of his body. A swell of motion caught his attention in the corner of his eye, and he held his arm up, noting with awe that it had begun to thicken as well. His eyes widened, bulging from more than air.  Both arms were inflating larger: biceps that had once been flimsy, floppy little things were rounding out, packing on what looked like pounds and pounds of meat as their radius swelled larger by the second.

Icicle let out a squeal of delight as the welcome pressure in his rectum doubled and redoubled again. The speed of the pump was picking up, the influx of air into his body intensifying. A groan slipped - or forced - past his lips as he moved his broadening hands down to his smoothly, rounded belly, his gut fast growing past the capacity of his lap to hold it. A wide, inflated sphere heavy with dense, well-packed air sat above a pair of thick, curvaceous thighs that even the sexiest of porn queens would kill for.

He giggled to himself as he caught sight of his reflection in the mirror. His buff arms flexed and peaked, their radii passing the thirty-inch mark as a pair of balloon-like pecs pushed out from his chest. Both of his pecs were fast approaching Midnight’s lovely breasts in size, and rested comfortably on the horizon of his belly. Said belly was, of course, far larger than it’d been mere seconds previously - with the constant influx of air from the pump below, he’d long since passed “pregnant” and was now starting to better resemble “fat” - except for the fact that there wasn’t a single fold of flab on him.

Icicle drifted back on the bed, chest heaving as he inhaled greedily. His cute asshole clenched and puckered around the insistent nozzle, his thick asscheeks clamping around it as they, too, bloated up larger and larger. Up and up he rose, his flanks thickening as each cheek of his growing, wobbly ass widened into a massive, soft pillow. Icicle struck another flexing pose, grinning as the veins on his reflection’s muscles bulged out hugely, in sharp contrast to the gently rolling, enormous curves the rest of him was gaining.

An intensely pleasurable sensation reminded him that there was something else growing, too. Icicle gasped in ecstasy, his eyes briefly rolling back with pleasure as he felt an incredibly sensitive hum of pleasure somewhere beneath the weight of his swelling gut. Seconds later, he saw it: a simply enormous, pre-drooling slab of stallion meat poking out from beneath the shadow of his balloon-shaped middle. Icicle moaned, feeling his luscious legs pushing apart as his already hefty nuts groaned and grew, demanding space, their contents sloshing as their volume increased to quarts, and then gallons.

He’d never felt such a nexus, such a bombshell of sexual pleasure. Groaning delightedly, Icicle began to knead and fondle his growing gut as its diameter passed his muzzle for height. He had to lean back, pressing himself heavily against the bed as his ass ballooned up and his belly weighed against his chest. It spilled over his lap - over everywhere, really - now, an enormous, bulbous sphere of wobbling curves and mass. Each twitch and shift of his hips frotted his growing cock against it; by now, though he could no longer see it, Icicle felt sure that his stallionhood must be at least two-thirds as tall as he was, and growing. The stream of precum dripping from his slit had fast become a river, a spray of its own, and his panting thrusts echoed the mechanical hum-thrum-fwum of the air pump as he grinded his shaft against the underside of his inflated gut like a mare in heat.

His asshole winked delightedly, its obscene suction slurping in even more of the nozzle into his rump. Icicle moaned, his eyelashes flittering as he jerked his hips forward and back. With each thrust, he felt the airy bloat of his eight-foot belly pressing down against his trembling shaft; with each pull, he felt the nozzle spread his ass even wider, the pressure of it pressing every one of his buttons as he let it fuck him mercilessly.

Fevered moans mixed with messy slaps as Icicle’s ass began to lift him completely off of the bed. He continued to frantically knead his belly, by now large enough to fit three or four ponies inside without breaking a sweat. The lovely air pressure - the pure tightness of it had him wheezing, sweat streaming down his face as his cock trembled and flexed. His nuts had to be the size of beach balls now, his “pecs” half again as large. Whimpers and soft, piercing moans slipped from his full lips, half whistles of escaping wind. His ass grinded against the nozzle as the air pump finally reached a roaring crescendo of pressure.

And as that pressure grew, and grew, and grew, Icicle felt a similar urgent tension building somewhere else. His shaft lurched, the muscles at the base of his cock locking up as he felt an inescapable rumbling begin deep in his balls. His arms and legs splayed wide from their massive thickness, his whole body dominated by his mountain of a gut, Icicle felt his jerking thrusts pick up in speed, his whole body slaving away to reach that final, incredible climax -

With a squeal of absolute pleasure, Icicle came. Thick ropes of spunk spewed from his shaft, painting the opposite wall and underside of his wagon-sized belly white with jizz. His massive balls, each one large enough to hold an ocean of seed all its own, were more than happy to share their load, making each eruption of spunk larger than the last. The tightness in Icicle’s body only intensified his pleasure, his eyes opening wide with joyous abandon as his thick limbs flexed and clenched, still massaging every inch of his gigantic body that they could reach.

Finally, Icicle felt himself coming down off of his peak. His cock gave a few final spasms - once, twice, three times - and then fell to a shuddering halt. With a grunt of effort, he rolled over onto his belly (which was now large enough to lift his body nearly to the ceiling) and, with some difficulty and no little regret, jerked the air nozzle out of his ass.

The pump fell silent a beat later, its motors winding down to a low, purring ambiance, almost smug. Icicle panted, his tongue lolling out of his mouth with exhaustion as he felt his enormous cock pressing between the mattress and his gigantic gut. He rocked his hips gently, and half-giggled, half-moaned when he felt a twinge of phantom arousal surge in his over-bloated body.

The weight of his pony-sized nuts was his next distraction - at least until the faraway sound of a door clicking open reached his eardrums. “Icicle?” he heard Midnight call. “I’m home!”

He blanched. Oh, no. Midnight couldn’t - shouldn’t be allowed to find out about him like this. To his rising horror, though, he realized that his belly was just too big to let him roll back down to his feet...and his ass had grown round and hefty enough to lodge his body firmly between the bed and the ceiling. He was well and truly stuck, incapable of doing anything but wiggling in place until he deflated like a balloon.

Icicle swallowed as he heard Midnight’s steady footsteps approaching. Well, he told himself, grinning nervously. Maybe she wouldn’t think too poorly of him…

Far below him, his cock gave a monstrous, lustful lurch. Icicle moaned as a healthy spurt of cum splattered against the far window, covering it completely.

Well, he thought, as Midnight’s hand began to turn the bedroom doorknob. At the very least, if she wanted him to be...he was very usable.