Bonus Chapter

After yet another long and tedious day you and Luna were once again drifting off to sleep, but this time there was no alarm to interrupt your shared dream.

Slowly, your eyes opened to find yourself in the dream world once again. You could see nothing but darkness. Sandwiching between you on both sides was two super-massive, universe sized rumps.

They felt squishy soft and warm to the touch, the soft fat folding around your body, pressing against every inch of your small form, with their immeasurable weight. With a little help from Luna, you could see these two enormous butts in all their glory whenever you wanted.

“Is our butts big enough for thee?” Luna inquired curiously.

‘Eh, I think they could be bigger’ you said… or tried to say through the mass of flab covering your face… entire body.

“Oh yes, we think our butts need to get bigger. So bony thin they are.”

With that, the two massive butts began to resume their expansion, growing together to reach out to the very walls of the universe, which were invisible.

The growing asses soon reached the walls, their soft fat deeply depressing against them. The more the butts grew the more squishy soft fat was being pushed back.

The walls held strong against the vast tide of growing booty meat pushing against them. However after about five minutes, small cracks here and there began to emerge over the wall. As the cheeks ever ballooned outward in size, with more and more fat being compressed the cracks began to slowly grow in size.

‘Come on Luna, tear down that wall.’ you tried to say, but only mumbled through her vast mass of fat.

A moment later there came a low rumble, before both asses went through a humongous growth spurt.

The walls of the universe shattered like glass, allowing the two astronomical sized butts to break free from their prison.

Countless see-through spheres floated in a dark void of nothing from all around the two giant butts of Luna. Each sphere contained an entire universe, with stars and other matter. Every passing second a new universe popped into existence. Some of them even had the gall to be bigger than Luna's butts.

“Heresy! Nothing can be bigger than our butts!” she roared.

Now with nothing in the way to impede their growth they began to expand. The two massive asses pulled the universes towards them, sucking them up and converting the mass into fat to add to the glory of their butts. The butts swelled larger and larger, growing faster and faster with each universe devoured. More and more fat, meat and weight added to their growing rumps.

The cosmic alicorn rumps grew so large the universe's began to look insignificant before their gigantic, ever growing size. First footballs, soon followed by tennis balls, then marbles, then a mere mist and then mere atoms. Now the universes were truly nothing, when compared to the might and glory of Luna’s super-massive butts.

Nonetheless, despite the universes insignificance size when compared to Luna’s butts, they were still doing their job, helping to swell the behemoth butts even larger in size. Providing unlimited growth to the rumps. Her rumps were now truly of incomprehensible size, swelling larger and larger without end, growing heavier and heavier, fatter and fatter, bigger and bigger.

The invisible walls of the very multiverse sped away from the growing rumps. The growing asses gave chase after the walls, expanding faster and faster to try meet them. Alas, the walls of the multiverse moved simply too fast. No matter how much universes the butts devoured to grow faster, the walls would still even move faster away.

This resulted in an unending chase. However you were not paying too much attention to that. Most of your attention was on the absolutely enormous asses that just kept growing and growing without end.

The warm softness of her massive rumps pressed against your naked form. Your tiny cock poked hard against the silky soft and warm rump before you. You decided to no longer just watch them grow, but to begin praising her glorious growing butt before you.

You made muffled moans into the expanding, unending mass. Your hands squeezed and rubbed her squishy soft flesh between your fingers. You licked, kissed, rubbed, and squeezed the massive butt before you, causing Luna to moan aloud and her butts to grow even faster to the point of nearly touching the walls of the multiverse.

Your hands dug deep into the thick uncountable layers of silky soft fat. The applied pressure from your hands deeply compressed down the immense layers of fat from her godly butt. Though, in perspective, you were merely pushing back a small amount of her flesh upon a tiny portion of her humongous rump. You were but a mere, tiny life form against an absolutely enormous, cosmic horse butt far bigger than even a universe.

Finally, your cock twitched hard, before with a loud groan you unleashed your seed, your cum staining only a tiny portion upon her rump.

Luna’s butts reacted positively to this by violently growth spurting to give the walls of the multiverse a hard slap, leaving large cracks upon it. Unfortunately, the walls quickly sped away like cowards shortly after.

‘I love you Luna,’ you tried to say through the unending, ever growing thickness, but all that came out was a mere mumble.

Luna uttered a loud, excited neigh, before her rumps overdrived in expansion, faster than ever before. The cheeks quickly grew out to slam against the walls of the multiverse, shattering them like glass.

Like harbingers of doom the two humongous butts of incomprehensible, and growing size loomed over the sea of multiverses spheres before them. Each see-through sphere was a mere football compared to Luna's colossal butts.

Hungrily Luna’s gargantuan butts pulled the multiverses towards them, devouring the multiverses and all their universes inside them like nothing. Luna’s butts swelled larger and larger, quickly growing in size to make the multiverses look like mere bacteria before the glory of her butts.

Each multiverse popping into existence was quickly devoured by Luna's rumps, helping them grow even larger at a quicker rate. Alas, there appeared to be no walls in this place, just an unending darkness for which Luna’s butts could truly grow and grow forever and ever, and be truly the biggest things to ever exist.

Luna’s butts were the most powerful force in all existence. Nothing could match the glory, the size and power of her ever growing butts. Countless multiverses were gobbled up by the butts, serving to only help the butts grow bigger and bigger without end.

“Uhhhh Luna, don’t get me wrong I love your growing butt show, but could we have sex now?” you inquired.

With that a vast wall of dark blue, which was Luna’s butt lifted off you, freeing your small form from it’s massive, uncountable weight.

You made to sit up, but were quickly brought back down into your prone state when an African elephant sized Luna slammed down upon you, in trapping you in darkness once again from under a massive ass.

“Make love to us, our little human,” she said in a hot breathy voice.

You humped upward to try reach her marehood, but it was completely useless. Her rump was simply too large, your cock poked between her massive, thick dark blue buns.

You uttered a loud, frustrated groan, angry you could not make love to her. Luna lifted her rump off your face to allow you to speak.

“Luna… I can’t make love to you, your butt is too big!” you shouted.

“Such heresy, Anon. This butt is not too big! If anything it is too small. Want us to make it grow?”

“No, just grow my dick so I can fuck it!” you shouted.

“It shall be done!” she boomed.

A loud moan left you, feeling your shaft grow in size, pressing into her hot, wet and soft, dripping wet marehood. Your growing cock was squeezed by the powerful walls of her alicorn vagina.

When your cock’s tip came to rest against her deepest barrier it finally stopped growing. Your thick and long cock was now encased by her hot marehood, your cock was squeezed tightly within her, her soft and wet walls massaging your member with a wonderful feeling of pulling and releasing.

Luna giggled happily, loving the sounds of your muffled grunts and moans into her massive ass. The mare then began to slowly lift her huge rump to the point of your tip nearly exiting her, before slamming her massive ass down hard upon you.

Repeatedly, without stop Luna slammed her massive, heavy rump upon you. If this was the waking world, you were pretty sure there would be nothing left of you but a pile of bloody jelly by now.

On and on, Luna slammed her enormous rump upon you. She laughed and moaned aloud, overjoyed that her massive rump did not break your pelvis nor caused terrible pain.

Her soft, heavy rump slamming upon you again and again was beginning to take its toll upon you. A powerful, tickling sensation coursed through your rod.

“Luna…. I’m about to cum,” came your voice, low and weak.

“Explode inside us our love!” she boomed, slamming her butt hard down upon you, her marehood squeezing your cock hard, demanding its seed.

With that, you uttered a muffled scream into her soft flabby butt as your cock came like a volcano, showering her insides with thick jet after jet of your creamy cum. Her marehood squeezed your member hard, milking it for more cum. Alas, the sheer amount of your cum was so much, it began to spurt out of her marehood showering you and her with thick strands of your creamy love cream.

Your cum went a great… well actually a very small distance like a river over the cosmic, ever growing butt, leaving a small white mark upon an unending sea of dark blue.

“Luna, you got the biggest, fattest, best butt of all existence,” you proudly proclaimed.

The Luna on top of you moaned aloud, quickly growing in size atop you. Your shaft began to fill her marehood less and less, until it eventually slipped out.

Now, a third butt of Luna’s began to grow between the two massive growing, multiverse eating butts, hoping to one day to be just as inconceivably large as them.

Unfortunately, there came a loud voice out of nowhere.

"Get up!" roared a feminine voice.

The both of you awoke to see Celestia standing next to your bed, looking angry with narrowed eyes.

“Sister, why?! We were having such a wonderful dream with our lover!?” she shouted in shock.

“Yeah!” you simply shouted.

“You two slept the whole weekend. It’s Monday, time to get up for work.”

“But sister, just let our butt grow a little bigger. So we can--

“No! Luna, you can dream about having Anon worshiping your multiverse eating asses tonight. But now, you got work.”

Both of you groaned, knowing she was right, but still hating her a little. So, you got up out of bed leaving behind sweet dreams of super-massive multiverse devouring, ever growing butts.