>>25242690K...a thing.
Life in Equestria was swell.
It had months since you had arrived unexpectedly in this place. The locals had been leery at first, but they had grown to accept you.
The first, however, was Rarity. The generous unicorn wasted no time offering you a place to stay, and you graciously accepted. Her finicky nature was grating, at first, though you quickly came to enjoy her company, and her, yours.
You also enjoyed her immense size. Oh you loved it very much.
Her gain had been gradual. A little extra snack here, and there, but once the two of you started sleeping together, she only gained faster. It might have something to do with all the treats you stuff her with as you lay together. She went from lean, to pudgy, pudgy to chubby, chubby to overweight, with no sign of her gain stopping. The sight turned you on immensely, such a cultured, refined pony letting herself go. Her cheeks would puff up adorably as she concentrated, fondling her double chin with a hoof. Her slim belly distended, swaying as she walked.
But the most impressive part of her was her rear end. It had already been impressive when she was still thin, a pair of thick hips that sensuously swayed as she walked, topped with a plush, curvy backside. You would always take a big handful of those delectable cheeks when you and Rarity made love.
Now it only grew bigger. Easily the width of three standard pony butts, it was a sight to see. Her stance was spread to account for her fat tummy, and every slight movement caused the huge orbs of butt flesh to jiggle and wobble. The dock of her tail had disappeared into the deep canyon of her ass, her styled tail running along the length of the crack. Her thick hind legs gradually widened, a crease forming where they met her wide hips. It was so huge you almost couldn’t wrap your arms around it as you and Rarity would fuck.