Soarin sucking his own giant cock to keep it from growing too big to fly.

Soarin’ panted as another tremor shook his body. He’d been riding a pleasantly warm thermal down toward Ponyville, and it seemed that what felt good for his coat felt good for…other things as well.

He landed on a nearby cloud and immediately got to work. With every second that his stallionhood went unattended, it grew another few inches, adding pound after pound of heavy stallion meat to his figure. Pegasus ponies flew through magic, not physical wingpower, but there was definitely a limit to how much cock even a Wonderbolt could carry in flight.

Soarin’ moaned as the orgasm hit. One hoof ran up and down his monstrous, two-foot shaft, rubbing his bulging medial ring as hard as it could. The other massaged his enormous ballsack. At first, he could only imagine the oceans of hot, stallion cum that lay in their depths just waiting to burst out - and then, as the first wave hit his throat, he didn’t have to imagine.

He pulled his mouth off with a wet pop, sputtering as cum clogged his mouth and throat alike. Another pony might have tried to swallow it all, but Soarin’ knew that if he swallowed every drop of seed his overproductive balls made, let alone every gallon, he’d never even make it off the ground.

Most of the rest of the orgasm fell onto the cloud, changing it from a whispy to a - solidly - milky white. The rest of it either had landed in Soarin’s mane, or had fallen to the earth below to give some (un)lucky pony a warm, sticky shower. It looked like his “attention” had had some positive effect - his stallionhood was down to around sixteen inches along - still big, but manageable - while his ballsack was “just” the size of a pair of grapefruits. But Soarin’ didn’t take the time to bask in the afterglow. He could already feel his “emptied” balls swelling up again with seed, and he had a schedule to keep.

So he flew, as fast as he could, with the wind whipping at his two-foot package as it bobbed and bounced beneath him. Within two minutes, though, sweat was running down his face from exertion. He could almost hear his gargantuan balls, now the size of watermelons, churning with cum beneath him. He could feel the immense pressure of a growing ocean of cum lapping up against the confining volume of his already-enormous balls. Meanwhile, his two-foot cock hadn’t wasted a single second, and had already swollen up to three and a half feet, leaking more and more precum all the while.

Once again panting rapidly, he glanced around for a cloud. Nothing, nothing, nothing - but there! In the distance!

His wings flapped harder than they’d ever flapped before, struggling to keep him and his growing stallionhood in the air. In the final throes of desperation, Soarin’ flipped into the third position of the Dazzlin’ Diamond Dive - flying forward on his back, his belly up toward the sky. His wings somehow managed to propel him forward as he desperately sucked on his growing shaft, his hooves pumping at its sides like they’d never pumped before.

He came again and again, each time coming up for a gasp of air as a shower of precum burst from his tip. Each time, his package stopped growing for a little while, and sometimes even shrunk down a bit, but it was never long before he felt the pressure growing in his balls again, his shaft throbbing as more and more cum filled up his balls to bursting.

Luckily, he’d positioned himself such that the steady flood of precum actually pushed him forward a bit - and within another five seconds, he saw that he was actually nearly there. Come on, he told himself, grunting around his swelling and throbbing head, his jaw cracking around its impossible size. His incredible nuts must have been the size of beanbag chairs at this point, and were dragging him down at least an inch every second with their huge weight. His wings were working overtime, but - would he make it? Just a little further, he thought. Just a little longer.

“Aaahhh!” he cried out, hitting the cloud with a bump, a roll, and a final orgasm. A geyser of cum surged from his tip, actually pushing the cloud - luckily, a firmer, wider specimen than the last one - down a few inches in the air with its force. Soarin’ panted as his seed showered back down on him, his melon-sized nuts shuddering as they put out rope after rope of thick, warm spooge into the air, finally stopping in growth as well.

Soarin’ took a deep breath and glanced down at his package. “Welp,” he said, swallowing. “Let’s hope that’s over.”

His stallionhood twitched once, though in amusement or mercy, Soarin’ couldn’t possibly tell.