Claiming the first of his herd.

It was extremely telling that the moment Isaac obtained absolute power, the first thing he did was find the most beautiful and powerful woman in the land, give her every incentive to fall in love and lust with him, give her gigantic tits, and fuck them with a gigantic cock.

But goddamn, there was something unbelievably hot about fucking two giant pure-white tits bigger than beanbag chairs as their owner moaned and squeezed them around his shaft. It was a primal delight that shot straight to his loins. And the knowledge that he'd made every single female across the entire world guaranteed to be deliciously busty was the icing on a very big, tasty cake!

Hearing Celestia's sweet, regal voice overcome with pleasure, meanwhile, was like an injection of pure, uncut sugar.

"Yes! Isaac! Please! Keep fuh- fucking my tits! They've been waiting so long for YOUUU! It's all been worth it so I can feel your big fucking human cock between them! S-So hot, so big, so MALE! Y-You're a fucking GOD!"

Between that aural ****, watching her gigantic mountainous mammaries jiggle with every thrust, roaming his hands all over them to feel their immense weight and softness, and having his brand-new enhanced dick completely buried from base to tip in impossibly warm, soft breast - on top of all the buildup to this with his own indulgent reality-warping - Isaac was doomed not to last long. "Mgh, you all love... dirty talking to spur on your man, don't you??"

"Yes, yes, yes!" Celestia cried out in pure joy. "My MAN! Not just a male but a MAN! Oh please please, let me be the first before you claim countless mares and subby stallions as your own, before the whole WORLD falls to their knees before you! Take what's rightfully yours! My perfect tits, my immortal body and mind... Everything I am belongs to ISAAC!"

That did it. His desire to claim, to take, to own, it was satisfied in that moment. His oversized cock swelled in anticipation, and his gigantically swollen balls tightened up incredibly. And then, the dam broke. The inaugural spurt of Isaac's new reality raced out of his cock in one sharp pump, smearing into the top of Celestia's cleavage before it overflowed and squelched out onto her face from the pressure. Celestia squealed in shameless glee and released her grip on her tits, letting them gracefully flop to either side of her chest, presenting her whole upper body to him to paint with each successive volley, while her hands reached beneath her breasts and down to her loins and his to frantically finger her pussy while gently cupping his balls to encourage them to keep cumming. Thick strands of white arced over Celestia's face, coating her white face in his human goop that piled up enough to block her big magenta eyes. Some of it seeped into her auroral mane, adding blasphemous streaks of white to the pastel colors of her eternally wavy divine hair. Celestia moaned as her own orgasm hit, juices spraying from her alicorn pussy and staining the bed behind Isaac.

By the time Isaac's cock slowed down and began to wilt, everything in a cone in front of Isaac's cock was covered in a layer of white. His enlarged balls had come with increased production, it seemed, and the evidence was all over the alicorn of the sun's neck and face. It had also come with a lot more pleasure, a lot more afterglow, and quite a bit of soreness in his loins and abdomen, his body not quite adjusted to pumping so much liquid in so little time. Plus, his cock felt sluggish and heavy now, like it wasn't going to spring back up anytime soon after an explosion like that.

Nothing he couldn't fix, though. "Ngh... Has my sexual stamina and staying power been steadily improving since I got here...?"

All of a sudden, his cock was back up and ready for more, throbbing proudly as the last dregs of cum still oozed from his tip. He felt barely winded now, too, like he'd barely jogged down the block rather than emptying the contents of his reproductive system. His balls felt fuller, too, ready to keep up the pace and go for more.

Celestia began to wipe the cum from her eyes and lick around her lips. Slightly worried that she might not enjoy it, Isaac muttered a quick question under his breath: "Has my semen become a delicious, slightly addictive, mild aphrodisiac that smells great and feels great on native fur and skin?"

The regal alicorn Princess immediately became more eager, bringing handfuls of his white goop to her lips and licking glob after glob onto her tongue, before rubbing some more into her cheeks and down onto her chest, sighing happily. "Oh, Isaac..." she murmured softly, gazing up at him lovingly before lowering her eyes to his cock. She licked her lips, perhaps subconsciously. "Mmm... I can't believe how perfect you are for us... Your size is great, your desires are great, even your cum tastes and feels great. I wonder if you arriving here was no freak accident at all, but in fact some other **** at work..."

Isaac chuckled bashfully, though his spine froze up a little at that. Did she realize that he was making this all happen? Would she be upset? Maybe he had underestimated her intelligence, even after all this sexualization...

"Maybe it's fate," she mused. "Maybe the collective wishes of our people have finally been answered. Or maybe I'm overanalyzing a grand coincidence." She sat up, her immense breasts sliding forward with her, and lovingly stroked his cock again while staring down into his eyes with her cum-stained, smiling face. "All I know for sure is... I hope this trend of good fortune continues, hmhm!"

Isaac **** himself to calm down a little. It wasn't like he could realistically get into trouble he couldn't 'ask' his way out of, anyway. "You and me both, Princess. You and me both..." His eyes roamed down her cum-stained, flushed, perverse body, wondering how else he could change things to make them hotter. An idea quickly formed in his mind. "You came, like, two times just from me titfucking you, huh?"

Celestia's posture changed, looking a little more drained and exhausted. The wetness between her thighs and sprayed out over the front of the royal throne-slash-love-nest intensified as well. The smile on her face was a bit more giddy. "What can I say? You were right, my huge alicorn tits are very sensitive, and having a real man's cock between them was a dream come true~." She squeezed his enormous dick for emphasis.

"Are all the sapient creatures of this world multi-orgasmic, cumming quickly but able to experience many orgasms in a row before getting tired?"

And now Celestia looked a lot more refreshed and energized, though she didn't look any less heated or soaking wet. "Hoping for a few more rounds, are we~?" she cooed, dodging the question in that telling way that might as well have been 'yes.' "I take it the people of your world aren't usually so lucky."

Isaac sheepishly shook his head. "No, I can't say our world is anywhere close to such a ripe sexual paradise as this one."

"Oh, it's not all fucking 24/7 here," Celestia remarked, immediately betraying her own point by craning her neck down to give the tip of his cock a quick suckle to taste the last strands of cum. "Mmm..." She removed his cock from her lips with a quiet 'pop.' "We still have lives to lead, ambitions, dreams, goals, families, politics, struggles, compromises... But we've also decided that it's easier to pursue a life worth living if we don't hold back our bodies' natural desires."

"Hm," Isaac hummed thoughtfully, glancing aside at one of Celestia's enormous tits. "Honestly... I've got a lot of pent-up desires, and all I really wanna do is indulge in them for a good long while."

"I don't think you'll find anyone who'll object to that," Celestia assured him with a slight grin. "You're from a more 'prudish' world, after all. You've got a lot of catching up to do if you want to fit into our society. And I hope that you'll find that all my little ponies are more than willing to help with whatever you need~." She scooted back on the bed and got up onto her knees before turning around, setting her giant tits down on the bed, and laying atop them like enormous twin cushions, flagging her tail to show off her ample rear and soaked pussy. "And~... if what you need happens to include stuffing us with your big, fat, human cock, then I can't see how that wouldn't work out for everybody~."

Isaac grinned and advanced on his knees towards her **** rear, enjoying how the rest of her body was still dwarfed by her breasts that she was laying on. Though now that he thought about it, the situation could use some balancing out. "You girls all have wide hips, big butts, and thick thighs to varying degrees, don't you?"

Celestia's lower half suddenly seemed to double in size, her sun-symbol cutie marks on her hips scaling up as there became more real estate to cover. While Celestia's ass had been nothing to scoff at before, now it was a pair of luxuriously soft bubbles sat atop thick, plush thighs that closed the gap her wider hips would have created between her legs. Still nowhere near the **** size of her breasts, but now the overall package was worthy of an ancient fertility goddess. Celestia didn't notice any difference, of course, and just giggled back at him. "As if you haven't noticed with all that 'pony-watching' you've been doing this past month~," she teased. "Though you should see my sister. She's an expert at 'mooning,' if you get my drift."

"Ahhh, she's got an ass as big as your tits, huh?" Isaac asked, knowing full-well the consequences.

"I wonder which of us would entice you more..." Celestia mused, wiggling her butt at him. "You'd think we'd be more similar, being sisters, but no - I got the tits, she got the ass. Though I suppose we're more complementary than overlapping in a lot of ways... I bet you two would get along swimmingly. We'll have to ask her once she wakes up this evening."

"Can't wait," Isaac agreed giddily, grinning wolfishly. Feeling like he was on a roll, he reached out and cupped Celestia's wet pussy, making her gasp and moan at his touch. "Do all you girls also have big, puffy, swollen pussies with big clits that you can perfectly control to squeeze around a cock?"

Celestia's cunt changed from a relatively normal-looking gash to a pornographically oversized pair of puffy white lips, twitching and drooling juices as her pink pearl of a clit peeked out against his exploring fingers. He felt her clench against his hand, trying to tighten around a cock that wasn't there yet. "P-Please, Isaac... You're teasing me again...!"

Pleading faux-innocence, Isaac replied, "I'm just marveling at all our anatomical differences." His hand drifted up between Celestia's enlarged ass cheeks, grazing against the hole between them. "And like I read before... Is it true that all the sapient creatures of this world have soft, tight, puffy assholes that always stay magically clean and feel orgasmic when stretched out by penetration?"

Celestia shuddered, not realizing that her rear hole had slightly engorged to become a small puffy ring between her cheeks, twitching eagerly trying to invite one of his fingers to sink in. "Y-You bastard..." she groaned, shuddering with lust. "Acting all clinical while you point out how we're practically made for sex... Please, stop teasing me and fuck me, human!"

Isaac lifted up his cock and lined it up with her fat, drooling cunt. "As you wish, Princess."