After another short recovery, Celestia's member was once more as hard as stone, ready to do as Celestia promised and breed the mare before her. "Are you ready to become a mother, and make me one too?" Celestia asked Twilight sensually, getting a quick nod, and a shiver of anticipation, from the younger mare as she rolled onto her back. Truly, Twilight's pussy was burning hotter than ever before from all the previous stimulation without release, making her crave a cock to fill her, and the heat-calming cum that came with it.

"Yes, please," Twilight responded simply, nodding her consent, "'breed me', I think it's said. Inseminate me, Celestia. Make me bear your offspring."

Hearing such a salacious, yet distinctly adorkably 'Twilight', thing from her once-innocent student, and knowing they both wanted the same thing, Celestia mounted Twilight again as the latter lay on her back, hind legs spread. In this position, they were chest to chest, muzzle to muzzle, with Celestia taking full advantage of that fact as she rubbed noses with her mate, before meeting her lips in a loving kiss.

As the Princess of the Sun kissed Twilight, her hips were meanwhile at work seeking her wanting entrance, humping gently until, a moment later, she felt a wet warmth on her flare. Knowing instinctively she'd found her target, Celestia shifted her hips forwards and pushed in slowly.

Twilight gasped as she felt something within her parting and stretching deeper into her belly the further Celestia pressed into her. At the feeling of Celestia's member spreading her marehood's muscles open for their first time, Twilight whimpered at the strange, mildly painful, and fairly uncomfortable, sensations in her maiden canal, biting her cannon to help cope with the mild cramping that came with it as Celestia slid ever deeper. The entry was extremely smooth though, with her being well-lubed given her intensely aroused and fertile state.

"Shh, it'll be OK soon...or do you need me to stop?" Celestia asked as she paused a few inches in, despite that being the last thing she wanted to do. She'd not had a virgin share her bed for a long time and, just like her ass, Twilight's pussy was very tight, but also nearly hot, as would be expected from a virgin mare in heat. She could feel Twilight's nearly crushingly-tight inner muscles grasping down on her cock desperately as they seemingly molded to it, before loosening again, adjusting to allow its first guest further entry.

"N-no, you can keep going," Twilight said, her head buzzing with pleasure already despite the discomfort. "Please?" The experience was almost overwhelming, but the sensation of being filled up in her most fecund time was almost addictive. The feeling of having something so perfectly paired to her needs within her, something long and hard for her desirous muscles to squeeze down on; something penetrating her after so many years and estruses unsatisfied. Something utterly satisfying spreading apart what lay between her legs.

"Of course love, but relax your muscles please. I can't get deeper with you so tensed up in there," Celestia said, and Twilight nodded, willing to do almost anything to get more of that satisfying fullness. It took a moment for Twilight to find the right muscles to control, but eventually loosened enough for the mounting mare to pull out just a bit, before continuing to sink deeper into the fertile warmth engulfing her length. The feeling of her going even deeper made Twilight whimper, her muscles spasming and squeezing down on Celestia's cock.

"Theeere we go...getting nice and deep inside you now..." Celestia said in a breathy tone, then wriggled her hips to make further entry easier, her head easing back again as she felt her medial ring press to Twilight's vulva. As that sensitive band of cartilage was soon brought into the soothing warmth as well with a little added pressure, it forced a moan from Celestia. Twilight moaned too as the wide ring rubbed over her clit on the way in, prompting a wink from it and a string of Twilight's fluids drooling from their union down to the bed.

Twilight found a pleasant buzzing starting in both her head and nether again like when Celestia had been up her ass, one that intensified more the deeper Celestia got, but this one was different; this sensation was much more deeply satisfying. She let loose a quiet moan as she felt full, like her instincts demanded of her, and in the correct hole now; felt like the mare nature built her to be, to accept a stallion's penis within her, receive his seed, then carry his foal. She pushed back eagerly into Celestia's insertion, neither stopping until Celestia's balls pressed to Twilight's asscheeks, her flare meanwhile pressing hard against something firm and very deep inside Twilight.

"Oooooh~" Celestia groaned out, eyes softly closed as she fully hilted her mate, feeling a tight little ring on her flare as she pressed to her furthest vaginal depths. Twilight too savored the feeling of being fully entered, her instincts screaming how right and good this was, rewarding her with another rush of pleasure hormones as she felt the distinctly male hardness deep inside her, warm and softly throbbing. She could swear she could feel Celestia's rapid pulse through her constricting walls, only making her realize just how real this was; that she was getting fucked by the princess's royal cock, and would soon be filled with her sperm. Her ovum would be fertilized by her stallion like a good mare's should be, and she would carry their young. Twilight only too eagerly anticipated it.

"I...I can f-feel your heart beating through your...p-penis..." Twilight absentmindedly said, gently pressing a hoof to the slight cylindrical bulge Celestia's hardness left in her lower belly. She had rubbed her pussy while both in and out of her heat before, but this felt like that, times twenty, and all so satisfyingly far within her instead of just at her entrance. "...I can feel you...so far up inside me too..."

"Mmmhm, I know that feeling all too well from each time I took a stallion to bed. Perhaps I should have another foal with a stallion too in the future, with your permission of course." Celestia mused, smiling at the fond, sensual memories she'd retained, even after so much time had passed since her last time with a stallion, and further past memories of the last time she'd allowed one to give her a foal.

Twilight, in her curious nature, wondered what it would feel like to have somepony ejaculating inside her, making her pregnant, breeding her, but she knew she wouldn't have too long to wait to find out. She soon focused on the now as Celestia slowly pulled her hips back, making a certain hunger grow within Twilight the more that was taken away; the overwhelming desire to have it all back, deep inside her again.

When her need was at its peak, when Twilight was about to beg for Celestia to give back what she'd merely had a taste of, she slowly slid back into Twilight, prompting a soft groan of pleasure from both. More and more stallion cock filled Twi again, its flare ending up kissing her cervix again. Celestia once more withdrew, leaving that hollow feeling once more needing to be filled, before she quickly entered Twilight again, then repeated the pattern further.

"Hmm-mmm...feels like your teats are full again..." Celestia cooed, before once again starting to milk Twilight with her magic, kneading the life-sustaining fluids from her, quiet splashes of mare-milk impacting the already-present fluid inside the container beneath her. The sensations of being milked only added that much more lovely stimulation to Twilight's already-overloaded mind, her back legs quivering.

Eventually they developed a rhythm, with Celestia pressing in to the hilt, and Twilight pushing back and up to help her get as deep as possible each time. The latter learned to enjoy the contrast of the desperate emptiness soon being rewarded with the satisfying filling, having Celestia's cock filling her up and leaving her feeling complete once again.

Hearing second-hoof accounts from her friends about how good sex during estrus felt was one thing, but their words couldn't describe how completely contenting it was. How right it felt to have something long and firm and thick sliding in and out of her fertile pussy, the insistent screaming of her mind for her to find a stallion quelled now that she had and he was breeding her...even if it wasn't quite a stallion atop her, nor a 'he'.

Each motion brought with it a wave of pleasure as Celestia stirred up her insides, Twilight starting to see why there was so much ado about sex, especially during the mating seasons when mares were more sensitive. They kept at their slow pace for a while before both wordlessly agreed to speed up, Celestia ramping up her humps to be that of a moderate pace now and Twilight ramming her hips back to accept her deeper. The moans and other pleasured sounds were more frequent now between them, Twilight's head pressing back into the pillow at how much nicer it felt to go just that little bit faster. "You, um, can go f-faster if you want. I d-don't mind," Twilight said, her cheeks having a gentle sex blush to them.

"Mmm, I'm so p-proud of you T-Twilight..." Celestia purred as she continued to claim her broodmare, balls slapping against her plush ass now as she sped up, "...able to take m-mmm-y full cock into all three holes? Not every mare could do that."

Twilight felt her cheeks flush warm from such a lewd compliment, and at hearing Celestia speaking so lasciviously, sure that her cheeks were glowing brightly as she looked away. "I, um, you feel really good all the way inside me too..." Twilight admitted, feeling Celestia maintaining the speed of before, "...b-but...can you p-please go a little f-faster again?"

Celestia simply nodded and ramped up her efforts, prompting a long moan from Twilight as she started to truly fuck her mare in earnest, her full thrusts growing harder yet. Celestia's balls slapped to Twilight's flanks loudly with each hilting thrust, the loud, wet pat-pat-pat reverberating in the high-ceiling room.

Twilight's pleasure exploded as Celestia's balls hammered her flanks, and her flaring dick churned her passage and pounded against her cervix like a battering ram, feeling as her medial ring rapidly passed over her winking clit. Without the spell, she knew she would have cum, probably multiple times, from that sensation of her 'stallion' flaring and readying to cum in her alone, but all she was able to do for then was enjoy the mini-orgasms she was permitted instead. It was almost torture to not be allowed to fully release when she needed it so badly, but she knew it was for the better. After all, she knew from previous masturbation sessions how intense a denied orgasm, or possibly chain of orgasms, could be when finally allowed, not to mention the increased chance of conception if sperm was introduced into her first before she came.

"A-alright...I'm getting...s-so close..." Celestia whispered passionately, "...r-ready to become a mother, and make me a s-sire again too?" The moment Twilight nodded, it wasn't two more humps before Celestia's muzzle pressed to Twilight's in another kiss as she froze up, her eyes sealing as she rammed herself into her mare hard enough that time that Twilight yelped into her mouth when it rammed hard into her innermost ring, sealing against Twilight's cervix. Just the thought of Celestia filling her up and making her a mother made Twilight hornier than ever, as she felt inch after inch of her flaring cock buried into her again and again.

Twi could swear Celestia's huge cockhead was pressing right behind her navel, but knew it was instead kissed right to the mouth of her hungry womb, ready to feed it a huge load of cum. Hearing the elder alicorn's pleasured sighs, feeling how rock-hard she was, especially her flare, and her near-scalding breaths washing through the fur on her neck...it all felt so very perfect.

"C-cumming! Take it all, my broodmaaaare!" Celestia groaned, before biting Twilight's ear as she rammed her hips home one last time. Twilight's insides were hot as an oven and ready to start baking, and the elder alicorn was more than ready to provide the foal-batter that was needed to start that little bun's eleven-plus months within it.

Twilight meanwhile felt a mild pain in her ear as Celestia bit it and hilted her again, feeling as her flare grew what felt like twofold inside her from its already impressive size. That sensation, of the thick hardness stretching so deep inside her, triggered a feeling of deep satisfaction as she felt her stallion flaring inside her fertile body. "Y-yes!" Twilight cried out as she felt Celestia's whole shaft and balls pulsating hard in a rhythm as she held deep, before finally, Twilight felt it.

Celestia let out an ear-muffled whinny and Twilight a quiet 'ah!' as she felt a great burst of warmth deep inside of her, then more and more, as well as the mighty pulsations of Celestia’s cock as her prodigious royal load pumped into her rapidly. She could swear the herm came just as much as the previous times despite this being her third orgasm within twenty minutes, if not somehow actually squirting even more of her virility into her, quite obviously wanting to make sure she was good and properly bred.

"H-ho-my-gosh, so that's what a pony ejaculating inside your womb during estrus feels like..." Twilight mused, loving each rapid throb and accompanying warm burst slamming against her cervix. It was beyond anything she'd ever felt before, the squirting of cum onto her most inner depths a balm that soothed everywhere it touched. The feeling of Celestia pulsing her semen inside her while she was in heat felt better than any orgasm she'd ever felt before, the sensations of being bred so utterly fulfilling that she couldn't even hope to compare it to anything else she'd ever felt, nor contain the sounds of pleasure it forced from her. "...ah...ahhhh...I love it!"

Twilight was rewarded with another mini-orgasm as Celestia continued to hump all throughout her own long, full orgasm. She kept squeezing down with her pussy, instinctively milking spurt after spurt of hot, sperm-rich alicorn cum from the twitching cock buried within her. She felt it decorating her insides a pearly off-white as Celestia nickered her pleasure, planting soft kisses on Twilight's ear after releasing her love-bite.

"Mmm, having a foal squirted into you feels pretty good for you too, huh?" Celestia asked after cumming for nearly half a minute. She stopped humping for a moment and slid out with a loud schli-pop of breaking suction, a small stream of her cum oozing from Twilight's spread lips as the massive flare keeping it all in slid out, the rest held deep inside. "How about we try something different?" Celestia only stopped humping for long enough to move Twilight onto her side with her magic, and to lift Twi's back leg and hold it against her own chest, before plunging right back into her still-gaping marehood.

Twilight moaned deeply when Celestia filled her again, her flare's ridge scraping against a particularly nice spot within her at the new angle. Twi let out another long moan and squeezed down on her inside, rocking her hips as well as she could in her position to keep her there. "There, there, a-aah-yes..." Twi whimpered desperately, clit winking and an off-white string of their combined fluids drooling from her to the bed.

Celestia kept humping away, seemingly lost to her bestial urges, only quiet grunts or muffled breeding whinnies coming from her throat. She kept a tight grip on Twilight's leg, her hips a flurry of rough, feral thrusts. "G-gonna-hah-gonna knock you up...make you carry my foals..." Celestia grunted out between thrusts, her voice deep and gruff.

Twilight was in awe of how lost her lover and ex-mentor was in the act of breeding her, and in awe of just how good it felt to get pounded by such a nice, big stallion dick. How full it made her feel, and how perfectly it rubbed her insides, Celestia's medial ring rubbing over her clit's hood each time it entered or exited her, and how her flare packed her first cumshot into her womb. "Yes, I want it...I wanna carry your foals..." Twilight mumbled out, feeling another hilting thrust filling her again, and getting that much closer to fulfilling her demands again.

It wasn't long before, working purely on the instinct to breed this fertile mare as much as possible, and with no concern for her partner's pleasure at this point, Celestia quickly worked herself to orgasm again within Twilight's nearly-hot pussy within a minute. Humping away with wanton thrusts, the elder mare whinnied out loud as she slammed home inside Twilight again and her swollen flare sealed against her deepest barrier, pumping out another hefty load of creamy stallion cum deep into her broodmare's fertile passage and womb as she bit at her neck this time.

Twilight, meanwhile, was entering a state of delirium from being fucked so much without stop, high on the endorphin and dopamine rush, relishing the feeling of more hot, virile cum washing deep inside her and cooling her estrus's burn. Her mind was focused only on the satisfaction of being bred, focused on each warm spurt of potent semen released and pooling deep inside her; focused on accepting her stallion's sperm into herself as she felt each jump that Celestia's cock made inside her. "I...I love this! I love your penis!" Twilight cried out as she squeezed down her muscles as well as she could, milking Celestia for her seed, craving it, focused on getting every last drop as far inside of herself as possible. She was rewarded for her actions when Celestia started softly kissing her bitten neck, getting a pleasured trill from Twilight at the sensations.

After another so-brief break to position Twilight so she was half-standing now, with her forehooves folded under her chest on the bed, hind hooves on the floor, and ass in the air, Celestia's larger form was now mounted over her in a variation of the position their feral ancestors made foals in. As the alabaster mare thrust into her depths once more, Twilight felt a thick fluid, undoubtedly some of Celestia's excess semen, squelching out of her pussy and down her hind legs, with the large stallionhood's reentry displacing some of the excessive amount already inside her while forcing the rest deeper. "H-holy hay, h-how are you still going? And how did you ejaculate so much?!" Twilight asked, but her only answer was a firm, hilting thrust from Celestia, as well as the accompanying burst of satisfaction and pleasure for her that came with it. Celestia apparently far beyond words now, the only sounds from her being the hard huffs of her breathing, and the occasional moan, or quiet nicker or whinny.

The feeling of Celestia's underbarrel grinding against her croup with each hump made Twilight groan at the primal satisfaction of having a pony mount her properly, feeling her thrusting away, still as hard as she had been before Twilight gave her a blowjob, even after cumming four times. So, instead of questioning how, her mind was soon pounded into a state of pleasured limbo, sex hormones flooding through her veins as she was fucked into mental oblivion.

Eventually, Celestia bit down again on Twilight's crest, yanked on it harshly, and thrust hard into her, Twilight giving a quiet yelp as she felt Celestia's swelling flare ram deeper than ever before inside her. She felt something deep being spread apart, her eyes closing at the blissful, if mildly painful, sensation of welcoming her mate as far inside of her as her stallionhood could get. Thanks to her estrus and the relaxation spell, she'd later realize, her cervix was almost totally dilated. Her innermost ring permitted Celestia's swollen flare past itself with no resistance, leaving it sitting at the base of the completely unprotected mouth of her fertile womb.

Celestia's flare was now poised to fuel Twilight's foal-factory directly, and the older mare tensed up again as her flare swelled up, locking her into Twilight's womb until her climax was done. She started to tremble again as orgasmic bliss once more took her, Celestia's body awash with the satisfaction and strong pleasure of once more finishing inside a fertile mare...and this time, directly into her womb itself.

The strange but right feeling of hard jets of cum impacting right against the back of her womb made Twilight give a deep, throaty moan as she felt an involuntary shiver go through her, the sensation of warm stallion spunk washing her furthest depths gratifying beyond description. She constantly rippled her inner muscles over the throbbing stallionhood on reflex, ramming her hips back to try to make that turgid flesh go even deeper, though Celestia's hips were already pressed as tightly to her own as equinely possible.

Celestia shuddered atop her as she just kept on dumping her nuts and glands into her mare, her longest, most extended orgasm yet coaxed on by the feeling of Twilight's cervix clamping down beneath her flare's ridge, her pussy kneading along her whole member on reflex, and her foal-oven itself suckling her flare. "Mmm-mmph, t-take it all..." Celestia said dreamily as she still came, "...c-cum for me...d-don't stop c-cumming. T-take it all...get pregnant for m-me!"

At that command, the spell preventing her climax was released, and Twilight was instantly launched into the most intense orgasm of her life, so intense it was like all those she'd been denied were hitting her all at once. A very loud whinny ripped from her throat as her whole body started spasming and she lost control of herself, her hind legs hiking up from the very intense pleasure overtaking her, leaving her face down and ass up to allow the sperm to drain deeper into her womb and oviducts.

The stimulation and denied climaxes of before made this build up to an extremely powerful climax. Twilight's pussy and womb contracted rapidly and rhythmically, her uterus greedily pulling in all the semen it could from Celestia's still-pulsating cock. Her rhythmic contractions drew her mate's many billions of sperm towards her right fallopian tube, where her egg, or possibly eggs, awaited to be fertilized by the most worthy of them.

As soon as one orgasm tapered down for Twilight, another one immediately started, the continued thrusting of Celestia's shaft as she once more started to breed her now overstimulating the young mare. "C-Cele..." Twilight mumbled, feeling as her belly expanded a bit from the sheer amount of the four full loads of thick alicorn foal-batter now filling her womb and being compacted into it with each thrust. She almost wanted to ask Celestia to stop, to end this nearly tormenting pleasure, but instead Twilight said something entirely different. "...please, m-more!"

Celestia curtly nodded as she kept thrusting at both Twilight's and her own instincts' demands, but the younger mare now seemed to be completely oblivious to everything else but the pleasure of being fucked and filled and bred, squeezing involuntarily around the cock that was so pleasuring her as she came and came, one orgasm's end only chaining into another's beginning. Eventually, it all became too much for her as the herm once more penetrated her cervix and directly fueled Twilight's foal-factory again, the throbbing and warmth making her cum again as she finally reached her threshold. Her moan cut off midway, and she went limp as her world went dark.

Once she gained enough of her senses back after whitewashing Twilight's uterus with another large cumshot, Celestia realized how limp Twilight was. She was concerned about how her near-constant moans had silenced, but couldn't stop her hips' movements despite how tired she herself was getting, still lost to her stallion breeding instincts. "T-Twi? Are y-you OK?" Celestia asked, but still couldn't compel herself to stop humping. After all, she could feel Twilight's rapid pulse through her pussy's walls, and thus knew that at least her heart was still beating, and could hear the rapid panting coming from her nose too.

A minute more of fucking the unconscious mare later, Celestia pierced her cervix again and dumped another smaller, yet still extremely virile, load right into Twilight's womb again, groaning her pleasure as she inseminated her once more. Her urge to breed was finally wilting after her sixth ejaculation, even her godly endurance and semen production having its limits.

Yet still she humped into the unconscious mare, knowing she still had at least one more good one in her, her instincts wanting to make sure Twilight was properly impregnated, despite the fact that the first ejaculation inside her marehood, though certainly the first one directly into her womb, had likely sealed the deal. Despite the fact that most of her additional cum was leaking out of Twilight now, and onto the totaled mattress instead, as opposed to staying inside her already stuffed womb and passage, she kept going. She could tell Twilight came again and again even while she was unconscious, from the tight, rhythmic, kneading grasps of her passage on her length and the quiet whimpers, her sleeping body still welcoming more of Celestia's sperm inside of her subconsciously.

Finally, minutes later, Celestia gave a wary groan as she flared, penetrating that loosened ring one last time, and her final load drooled out of her and into Twilight's uterus, a mostly-clear, thin, paltry amount that was likely barely half an ounce, her body completely drained as she dry-pulsed the rest of the time. After her seventh orgasm, she finally slid her wilting cock from Twilight's again-orgasming pussy, the still-swollen flare immediately followed by a deluge of her cum. "Oh no, we...we can't have that..." Celestia said tiredly, and, with a sigh and a smile, lit her horn and used a magic rod to push all her semen up into Twilight's womb, before sealing her cervix with a small force-field spell to keep all her cum inside her; though she knew she'd likely already fertilized her, it didn't hurt to make sure, she thought. "...no, you need all that to make our foal."

Celestia then added, as an afterthought, "Oh, and you can stop cumming now, love. I think you've done all you can to bring my sperm deeper." As Celestia said that, Twilight quickly collapsed to the bed, her tense, orgasmic expression turning to a small smile instead as the spell was nullified.

Now thoroughly drained and satisfied, and certain Twilight was too, with her pent-up libido spent entirely in the hour of constant fucking - and that's not counting the foreplay - Celestia curled up around Twilight, making the smaller mare the little spoon. A hoof soon rubbed over Twi's belly, finding that it was slightly bulging as though she was already partially into the pregnancy. "Oooh, I put a lot into you, didn't I? You're going to be with my foal for sure." Celestia cooed, rubbing that squishy mass of cum through Twilight's abdomen, knowing that soon she'd be doing the same when Twilight's belly swelled up with her foal instead in the coming months; that she'd be feeling her developing child there instead of just her semen.

Knowing she only had enough time for a short nap before she'd need to lower the sun, looking out the window to see the sun lowering in the evening sky already, and rather exhausted after such a performance and so many orgasms, Celestia closed her eyes as she spooned with Twilight. Soon, her dreams were alight with the possibilities of what their foal or foals could look like, with Twilight dreaming the same.

Both dreaming of the future they would have together, sparked by this intimate afternoon, and lust fulfilled.

Author's Note

Mmm, nothing quite like a nice, hot mare breeding...