>>5527428

>"Oh Luna, please...just let me...need to rest..." she pants and moans  "Please...begging you..."
>Nineteen hours.  She's ready to tap out, or at least that's what she's says.  You know she's exhausted.  She stinks of sweat and sex, having had so many orgasms that she's unable to distinguish pleasure and pain anymore
>But you know how this game is played., and that no matter what's coming out of her mouth, if you stopped this, you'd never hear the end of it. Nothing she's said is even remotely close to the safeword
>"Blueblood." A pony she despises so horribly that the only way she would say his name is in the event of a dire emergency.
>When she wants to stop most desperately, you're to keep going, no matter what she says unless it's the safeword.
>The magic spells have a built-in time limit, 24 hours, or until you remove the cattle tag on her ear (actually a spell inhibitor), whichever comes first.  Sweetie's spending the weekend with Apple Bloom, and the shop is closed for the next three days, which she'll probably need to recover from this at an absolute minimum. Her social calendar is completely clear.
>The last time you played, a month ago, she managed to go for almost this long.  today you're going to see if she can last a full twenty. If she can go that long, you'll see if she can go to 21.  One way or another, you're going to try to get her through the full 24 hours if it kills both of you
>"No, you have to keep going." You turn the pumps on just a bit higher, and turn the vibrator plug in her ass up slightly, and you kneel down and wrap an arm around her supportively. She presses her face into your chest and utters a cry that's halfway between a moan of pleasure and an agonized scream as she cums again, her body pushed almost beyond the limits of pony endurance
>But not hers.  That's the whole point.  
>Her hips spasm and roll as she mewls in a mixture of pleasure and agony, and her marecock floods the cylinder with fresh hot cum. Over the last hour alone her huge, magically-amplified cock has generated at least a gallon, and her huge bovine tits at least that much milk.  
>She's drinking almost continuously--every few minutes, you're holding up another bottle of the high-powered electrolyte replacer (semen-textured and flavored, as per Rarity's specifications) that Twilight designed, and she bolts it.  Bookhorse was very specific that you watch for any signs of dehydration.
>Sparkle wants both the milk AND the semen.  For science.  You're not convinced she's not simply taking a bath in it or pouring it over pancakes.  Purple Smart has weird tastes.  
>Also, she said something about wanting to understand altered states and their effect on spellcasting.  You wonder if she'd be interested in trying this for herself
>She drinks as much of the thick gelatinous stuff as she can stand and then some and you pull her head in toward yours.  You kiss her forehead.  Her face is slick with sweat and drool, and Squiggletail's hair is lank and wet and hot.  She's an absolute mess.
>She's never looked more beautiful than she does right now. 
>"You're doing awesome, honey," you tell her.  You check her restraints and make sure she's got adequate bloodflow.  
>"So tired," she pants and moans. "Hurts.  W-w-want to stop...pl-please..."  Her "please" comes out like a high-pitched sob.  You smile, and then you turn the pumps up a bit higher. Rarara's at 72 percent--you wonder if she can stand 90.  You're both going to find out today 
>You kiss her, your tongues playing.  You reach down and your hand finds her tight, swollen balls, while your other caresses her soft, swollen tits.  She's only a few minutes away from yet another climax.  You kiss her again.  "Let me help you out.  Make it feel better for you." 
>She moans as you kiss your way down her neck, and you taste the salt of her exertions. Your lips glide over the mounds of her tits, around the pump sucking rhythmically away at her nipples.  A bit of milk leaks out of one as you temporarily break the seal, and you lick the droplets away.  
>It's thick and sweet--maybe you DO understand why Twi would want to drink it, it's fucking delicious.
>All the while, your hand is kneading and stroking and holding her huge, hot marenuts--they're slick with sweat and vacuum pump lube, and the skin feels like velvet, smooth and soft and delicate.  Your tongue burrows in her navel, and she moans, and you continue your journey southward, kissing your way down her furry belly to her crotch.
>Her latex-clad legs are spread, restrained, the pump suckling rythmically at her huge, swollen marecock--the plastic sleeve isn't quite big enough to go all the way down, and she rolls her hips and thrusts uselessly into the sleeve, her body unable to decide whether it wants more or less of the sensations blowing through it.
>Your nostrils are filled with the heavy smells of her sweat and musk, heady and sweet like incense.
>You smile and blow on her heavy, wet sack, and she moans. Her cock twitches.  "You...you son of a bitch," she pants. And one by one, you suck each of her heavy balls into your mouth, letting your lips and tongue playing over them.
>She tastes heavenly. You loop your fingers around her twitching cock beneath the plastic sleeve and stroke it gently as you suck her beautiful, exquisite balls.  "I'm going to get you for this," she half moans, half sobs.  "I'm going to--ahhhn--rail you until you can't walk..."
>"Promise promises," you murmur into her sack, humming.  Her hips roll and thrust, and you lick your way down the sweaty ridge of her balls until you finally find the end of the great, jeweled plug completely filling her asshole, stretching her sphincter wide.  You kiss it, and your tongue finds and gently plays with the flesh stretched taut around it.  Her asshole twitches against your tongue
>She tastes of sweat and sex, of succulent primal madness.  You'd be happy to spend eternity tasting nothing else. 
>You look up at her, your hand working gently at the base and shaft of her cock and your mouth working her balls. >Her mouth is open and panting, a perfect O of mingled pleasure and pain, her eyes wide and staring into yours. Her breasts heave with each heavy breath, her eyes roll back into her head.  "i'm...oh luna I'm about to...cumming ...can't...can't stop...don't wanna..." she sobs, tears pouring down her face. "Don't wanna..." 
>Your hand strokes her pulsing cock faster.  "It's okay, baby, just cum.  Don't fight it.  It's easier if you don't fight it..." You kiss and lick her balls and the base of her cock.  "Cum for me, baby...fill it up..." 
>And with a final cry her resistance gives out, and she shudders through another orgasm, screaming as her abused body fills with pleasure and pain intermingled.  Her balls gurgle audibly.  The cup fills with cup after cup of hot thick marecum, and you marvel at the warmth pouring from the tube.  The cups on her breasts fill with milk, pint after pint
>And finally, after an eternity, it ends, and she sobs and moans, sagging back, her mouth open.  A fresh sheen of sweat coats her body.
>You give her balls one last kiss, and stand back up.  you pull her into a hot, wet kiss.  "You bastard," she whispers, a silvery thread of saliva connecting your lips as you pull away.  She breaks it with a lick, and then abruptly leans in to lick your lips.  She pants and moans at the smell and taste of her own flesh on your lips.
>You hold up another quart bottle of electrolyte replacer, and she drinks the thick stuff greedily.  "gonna...suck this out of you myself," she gasps between swallows. "And I promise I won't stop with one or two..."
>"I'm looking forward to it," you say.  "And you know what?" You gwesture at the timer on the wall.   "Congratulaions are in order, honey. 20 hours.  You've beaten your own record."
>"Yay," she says, mock-imitating her friend Flutteshy.  She's already building to another orgasm,and she sobs in mingled pleasure and pain.
>"Now," you say, turning the pumps and vibrating butt plug up a bit higher.  "Let's see if you can get to 21..."