“I didn’t tell you to stop, Sister…”

PLAP!

PLAP!!

PLAP!!!

Their motions blurred into one. Luna sat, pinned atop her complaining mattress. It squeaked incessantly with every grinding gyration of her sister’s pounding plot. Celestia’s buffeting bosom pummelled the princess of the night’s shaking skull, stifling the smaller alicorn. Luna could barely breathe as her entire face was enveloped in her squatting sister’s doughy flesh. Celestia’s meaty mammaries retreated, only to return a moment later with another jiggling slap. The fatty flesh was relentless as it easily eclipsed Luna’s ability to suckle, covering her cranium with the all-consuming rays of the smothering sun.

Celestia’s mouth was quivering as she hooked her spotless ivory teeth over her alabaster lip in an attempt to suppress her own moans. She smirked. Pleasure was building up within her, exacerbated with each push of her rippling rump. Celestia lathered Luna with her jostling undercarriage, the older alicorn shivering with every thrust; each cosmic collision of her planetary plot rewarded her with Luna’s trembling teeth tensing upon her titanic teats. Celestia’s gropeable glands spurted multitudes of milk with each salacious squirm of her sisters waggling hips. The younger sibling did her best to drink up, nibbling upon her sister’s tender nipples, but try as she might, the small alicorn couldn’t keep up with her sister’s milk production.

Her udders glistened with perspiration; a result of the sisters’ passionate moments together, as they undulated and rippled with each rhythmic roll of Celestia’s hips. Her movements were like some heavenly dance, one which gradually picked up steam as her arousal mounted with each strike of her mashing metronome. Luna, lost in their scale, allowed her sister’s buxom bosom to act like bouncing blinders. They smothered her entire skull and left only her svelte horn behind, to peek betwixt the bubbly baps. The elder alicorn rode her sister’s muzzle with lustful abandon, completely and utterly lost in the moment. Luna eagerly lapped up her sister’s leaking lactate, and let out a guttural sound of blissful delight. She was no doubt enjoying the sweet solution, which was fuelled by cake, icing, and other such indulgences that had rounded Celestia’s rump over her mostly sedentary century-spanning rule. The older alicorn’s twin cheeks slammed together like a pair of water balloons; soft claps filled the air like two colliding waves. When her glutes parted, they gave a fleeting glance at her pert ponut and plump pussy, before the snug space sealed up as the next blow began. Lewd sounds joined the duo’s impassioned vocalisation. Celestia felt her heart gently tapping against her sternum in the nirvana-like embrace of her sister sloppily slurping upon her bloated boobies.

Celestia’s production was too much for even Luna to handle; milk spurted from her maw faster than she could swallow it, as the pressure of her sister’s pounding caused it to spurt from the corners of her glugging gob. The blue alicorn’s stomach sloshed with copious amounts of the curdling fluid; she was entirely at the mercy of her sister’s pelvic waltz. Celestia felt her impacts bleed through Luna’s body as her movements echoed off of the creaking springs of their shared bed. The force of their shared sexual strikes caused Luna’s hind legs to come together, making her perfectly maintained hooves clap lightly against Celestia’s shoulders. It was as if the mare was giving a tentative hug, further increasing the amount of physical contact in the sisters’ wobbling waltz.

The two sisters were erotically entwined. Their motions became symmetrical, as Celestia enjoyed the resonating feeling of her padded plot, which shuddered with little aftershocks after each of her deviant dabs. She continued wordlessly, only breathing in Luna’s affectionate company, as the smaller princess teased and played with her sister’s gargantuan groin ornaments. Their progress became heated, and like a day breaking over the horizon, a fun and debaucherous thought tickled Celestia’s ancient mind. She pondered, continuing to pound like a piston in the meantime, until it was a certainty; a bruise the shape of luna’s slender face would more than likely be imprinted on her rather impressionable orbs.

Celestia mulled over her thoughts for a moment, before, without a word, she slammed her swan coloured pillows down and began to smother a very surprised Luna. The mare of the night did not expect the betrayal, and began to thump her forehooves against her sister’s flapping fun bags in an attempt to push the springy melons away from her suffocating snout. It took Luna a moment to process the act, before she realised the divine bust was not going to ascend again. This attempt on her muzzle prompted her sputter out a suppressed meep of protest, one that did little more than echo off Celestia’s cleavage as a ticklish raspberry. The raunchy sound was followed up with a spasming fight, as Luna began to struggle beneath her larger sibling, before suddenly going slack as the fightbled from her and she accepted drowning under the adipose-rich organs. Luna was trapped with the stench of her sister’s own arousal and natural musk. She succumbed to her situation with a fluttering flail, and became still.

“It seems the sun can eclipse the moon, dear Sister” Celestia exclaimed in a gloating and domineering voice. She wiggled her hips, expecting her sister to shriek some juvenile jab back at her, but the lunar mare remained silent. Celestia kept the pressure on for a moment, an eyebrow cocked, expecting her sister’s struggle to renew as Luna tried to buck off her opulent oppressor’s buxom body. But no fight came, and Celestia’s confident face shifted into one of fear as a horrifying thought crossed her mind, and slowly realised that Luna might not have been faking.

“Luna? Luna! Are you okay?” A suddenly worried Celestia blurted out. For a second, she thought she might have overdone it. The alicorn jumped up almost drunkenly, stumbling to her hooves in a desperate attempt to give her sister some space. The mare sprung to life, and no sooner did the punishing posterior leave her wheezing mouth, did Luna come alive with a gargling second wind. Coughing gently, she cleared her lungs of milk that had gone down the wrong way from her surprise struggle snuggle, and replied with a slow steamy breath…

“I didn’t tell you to stop, Sister…”