Booming Rainbows

You have seen horrible things… horrible things no man should never ever see. The things you have seen will haunt you for the rest of your life.

But that was then, now it was a sunny day in this new Equestria, thanks to some help from Discord, who felt pity for you over the horror you endured. Today you were sitting on a wooden bench in a park just outside Ponyville. At this time of day on a workday like this there was very few… of these horse women… ponies or whatever these terrifying aliens call themselves around here.

The only reason you aren't totally pissing your pants right now is because these ponies seem far nicer than the last ones, at least they didn’t outright demand sex nor invade your personal space… much. Okay, your first encounter with these new ponies could have gone better and that was what drove them to go all touchy feely with you. For the moment you saw them you chose to run away screaming into the Everfree Forest, the horrors you seen in the other Equestria were far worse than whatever lies in the Everfree Forest.

Of course, the ponies didn’t let you run away. The massive giant known as Fluttershy ended up grabbing you and stuffing your head between a pair of absolutely massive breasts. You struggled, crying as you tried to break free from her grasp for quite some time, all the while Fluttershy kept saying over and over again ‘Nopony is going to rape you.’

She even offered to breastfeed you when you eventually calmed down, but you politely declined.

Even after learning that these ponies would not outright rape you, you took the precaution to wear a grey, hooded robe to cover each and every inch of your exposed skin, just to make sure these ponies don’t go insane at the sight of it.

While these mares didn’t outright demand you strip naked and hump them, they still would do passive things to try seduce you into doing the deed with them. Such as the light blue horse woman about the same height as yourself, who had a rainbow mane sitting on the far side of the bench, who only wore a pair of red panties and a small red bra to cover herself. This mare needed no introduction, she was Rainbow Dash and she wanted you to cum inside her.

Her body in general was quite petite in normal mode. She was well toned, her backside was far smaller than most of the ridiculously large asses that most ponies just parade without shame and her breasts were pleasantly of small cup size, unlike the other ponies’ boobs that were as big as watermelons, if not even bigger. Upon her back was a set of folded, feathery wings.

Oh, she was whistling nonchalantly and pretending she wasn’t up to anything, but you knew that she was up to no good. For she was slowly, but surely growing bigger and bigger in an attempt to seduce you into cumming inside her. Inch by inch, she rose higher into the air, while at the same time the small features of her body assumed greater and greater size, her small breasts were slowly ballooning outward, her thin ass was slowly but surely growing in mass, squishy soft flesh adding to her growing rump to overshadow the firm muscle beneath. Her bra and panties seemed to stretch without end, seemingly growing alongside her ever expanding body.

"Nice day where having Anon, isn't it?” spoke her tomboyish voice, in a somewhat nervous tone.

‘Oh, here comes the small talk.’ you thought bitterly.

The mare sighed sadly when you said nothing in response other than a grunt.

Several minutes went by, a dark shadow now loomed over you, the bench beneath you somehow stood strong, despite the fact there was literally a fifty feet tall giant blue horse woman with a big blue, bouncy castle ass and huge, monster truck sized breasts.

You would be crushed beneath her ballooning, massive ass if the bench had not been magically elongating length ways as she grew in size, the only downside was you could no longer sit back, due to the seat itself beneath expanding in size too, to help accommodate the growing mass that was Rainbow Dash’s ass.

Also, you can’t safely get off the bench without breaking your legs anymore, due to the twenty foot drop, that was only becoming further and further as Rainbow continued to grow in size. This was no problem for Rainbow, since her feet still touched the ground, due to her elongating legs, growing thicker as her thighs grew outward while her rump became ever bigger.

Rainbow grew more and more without stop, her cheeks and breasts growing into truly gigantic proportions. Her efforts to get your attention never seemed to relent, her body in mere minutes became a small mountain, but even then she had not given up, instead choosing to grow her body even further, her ass and breasts becoming fatter and fatter, bigger and bigger, heavier and heavier. Her plan was simple, the bigger she becomes, the more sexy she thinks she is for you.

You tolerated the endlessly growing Rainbow Dash, until it began to become unbearably cold due to how high you were in the air. Rainbow Dash was now about the size of Mount Everest, if not even bigger. The squishy soft flesh of her enormous tits and ass now jiggled wildly in the strong wind.

“Stop growing! Shrink down!” you shouted.

“Stop growing?! You don’t like me being big?” came her powerful echoing voice across the land.

“Listen to me Rainbow Dash, there will never be any cum between us!”

The giant blue mare wailed in grief, burying her head into her hands, crying in anguish over your rejection of cum. Rainbow’s body began to rapidly shrink, along with the bench becoming shorter and shorter.

You held strong with your arms crossed, heart cold as ice as the mare continued to grieve. Eventually, the bench returned to its normal size and your feet could touch the ground again, along with Rainbow Dash herself the same height as yourself, her ass and tits returned to their normal, small size.

“I’m sorry Rainbow, but I just don’t like penises.”

Rainbow turned to look at you with a hateful glare. “I’m a girl!” she shouted.

“I know, but you have a futa penis.”

“No I fucking don’t! And what the fuck is a futa penis?! A penis is a penis! There’s no such thing as a futa penis!” she roared, cracking her fists together.

“You do have a futa penis, but it’s invisible.”

“No! I don’t! Look!” she pulled down her panties, and then waved her hand over her exposed crotch, and her hand didn’t seem to bump off against anything.

“It’s flaccid.” you stated firmly.

“FOR THE LAST TIME I DON’T HAVE A PENIS!” she roared, her rainbow mane turning into a blazing fire.

You whimpered in fear. “Okay… but can I test to see if you don’t have a futa penis?” you spoke in a low voice.

A bright red blush came upon her face. “Oh… ummmmm…. sure Anon.” she said softly, the fire in her mane extinguishing, returning to its normal rainbow colors.

You lowered your right hand over her marehood, quickly feeling around the general area to try find a cock and balls. To your immense relief, you found no secondary male organ on this mare… she was female and only female.

“You don’t have a… penis?” came your voice, low and weak.

“Of course I don’t have a penis! I’m a girl!” she spoke in a raised voice.

You sighed deeply. “I’m sorry Rainbow, I’ll just go.”

You made to stand up and walk away. You did indeed managed to stand up, however you didn’t move away from the bench when you felt something silky soft take hold of your hand.

You turned around to see Rainbow giving you a warm smile, holding your hand.

“I forgive you, Anon.” she spoke softly.

“I’m so sorry Rainbow Dash, I’ll cum inside you!” you shouted, tearing the robe off yourself and throwing it into yonder nearby bush.

Rainbow made a sound like a squeaking dog chew toy, before her body skyrocketed in height, growing as large as an african elephant with a pair of beach balls sized tits and a massive big blue ass.

You screamed in terror as the massive mare lunged forward, tackling you to the ground to pin you down from under her immense weight. You were thankful that these ponies bodies provided magical protection to those they want sex with, otherwise you would be little more than a bloody pile of broken bones and squishy mush.

From underneath her you could not move an inch. You sighed in bliss over and over again, basking in the amazing feeling of the warm, heavy softness pressing down on each and every inch of your small body. Until, you remembered you were meant to be having sex with this mare.

“Uh, Rainbow this feels nice and all. But how am I supposed to cum inside you? you inquired.

“Either by me growing your dick bigger, or by you coming inside me to cum inside me while inside me.” she said sexfully.

“Hmm, I need to think which one. Cum inside you while inside you, or cum inside you while outside you with a big dick?”

Whatever your decision, you were assured your asshole was safe from a massive, long and thick futa penis going up it.