"Twilight, my love, could you please come in here?" Celestia called, with Twilight closing the thick tome she was reading and entering their shared bedroom. She was about six months pregnant, and she was really starting to show that she was carrying twins now, as well as able to feel the growing weight of said royal alicorn twins forming inside her nurturing womb. The wearying burden of a pregnancy with them, combined with her exhausting royal tasks and the chill of autumn weather, was a trial, but one she only too willingly undertook for the rewards to come in about five to six more months.

Rumors had been circulating among ponies for months now, since Twilight had started to show and was obviously, visibly pregnant. Only a very select few ponies knew who the foals' real sire was, and all of them were sworn to secrecy. Her and Celestia's dating had also been kept a secret, though it was easily observed to everypony how much more time she was spending around the castle since getting pregnant.

The rumors born from that fact ranged from Twilight having a secret relationship with a guard stationed in Canterlot Castle, maybe even Flash Sentry, to her secret amour instead being the castle chef, who vehemently denied such, or even one of the princesses. They ran the gamut of being plausible, like the guard or chef, or one of the princesses, to ridiculous, such as the one about Twilight, Celestia, and Luna actually having the entire Royal Guard as their own personal harem and stud farm, to use as they pleased, and that was how she'd gotten pregnant with the foal or foals of an unknown sire, or sires.

Twilight chuckled as she thought of the ludicrous things the rumor mill ground out, when the truth was so simple, shaking her head as she walked to the bed. Upon it laid Celestia, lacking her usual regalia, looking rather serene as she laid there on her side with her eyes closed, her wings spread wide in a position of pure comfort. She had also disabled the illusion spell on her male parts, as she often did when alone, leaving her looking as natural as she had been born.

This made Twilight smile as she saw her lover so at ease, indeed the first pony in centuries to have the privilege of seeing her this way. She felt so special, so gifted to get to see Celestia as she truly was; to be trusted so much to be let in on the lead princess's biggest secret, and indeed get to indulge upon it nearly whenever she pleased. Celestia was always so eager to give her her ‘big secret’, too.

Celestia soon opened her eyes, raised her head, and looked over to where the approaching, heavy hoofsteps came from, smiling as brightly as her sun shone as she saw the mare who brought such bright joy to her life, the love she felt for her burning as hot as the celestial ball of fire she controlled. Soon, their lips met in a chaste but loving kiss, Celestia's heart melting as Twilight once more showed her love for her, and she showed hers in kind. "Hello, Twilight," Celestia said, her words dripping with affection as thick as honey.

"Hi, love." Twilight replied, giving Celestia a smoldering gaze in return, before, once more, their lips met, just a bit more firmly this time. Before it could get anymore heated, though, Celestia broke it, a brief flash of disappointment crossing Twilight's visage. They'd just finished one of their dinner dates, just the two of them, laughing and enjoying their time together as they always did. This time, however, Celestia had been acting suspiciously, though not in an alarming way. Just a little different, in a way only somepony as astute, and as close to her as Twilight was, would notice. She knew something was up, but it likely wasn't anything negative.

"So, why did you call me?" Twilight asked, a faint smile still on her face. She was close to her marefriend, and she couldn't be happier to be pressed flank to flank* with her lover.

Instead of answering her immediately, Celestia just gave a little smile and met her lips to those of her lover and broodmare again. "So," Celestia said, "you love me, right?"

Twilight was somewhat baffled by the question. The previous half of a year that they'd spent dating, and how well they were together as a couple - not to mention how often they verbally, physically, or sexually showed their love for one another - seemingly made that shared sentiment quite obvious. "Of course I love you, Celestia," Twilight deadpanned, "Why do you even need to ask me that? You know just how head over hooves I am for you!" She then placed her own hoof on her very swollen belly, heavy with her lover's foals, "Not to mention the fact I'm carrying our foals, and how wonderful that is too...how could you not know the answer? I'm crazy about you!"

Celestia chuckled a bit at that outburst, smiling as she placed her hoof atop Twilight's on her womb. "Yeah, funny how the catalyst for our relationship was the alicorn mating season coming around. Of course, we felt for each other even before, but my lust for you just set it over."

"Oh and what a night that was, you rutting me until you couldn't anymore...six times in a row, even after your orgasm during foreplay," Twilight said, smiling as she felt one of the twins kicking against her hoof, "and it most certainly bore fruit."

"Fruit that nopony but you could have borne for me," Celestia said, before lifting the wing that hadn't moved since she'd come in. On the bed rested a small mahogany box, bearing the seal of the Crystal Empire. "Something I'd like to reciprocate."

Celestia pushed the box towards Twilight, before opening it with her wing. Inside were two light-blue stones crafted into miniature representations of the Crystal Heart, set in golden horn-rings. "These are small fragments of the Crystal Heart from the Crystal Empire, given freely by the sentient artifact itself, and bequeathed to me by Princess Cadenza and Prince Shining Armor themselves at its behest. A gift to us."

Twilight was astounded, watching as Celestia gently removed one of the rings from the box, with it giving off a brief, gentle, white pulse of light on contact with her hoof. "The Crystal Heart can sense the love between two ponies and store it, then releasing it as positive and protective energy to everypony near it, in a magnitude as strong as their love is for each other. The powerful strength of the love between Shining Armor and Cadance helps keep the entire Crystal Empire protected, and spreads love through all the crystal ponies' hearts."

Holding up the ring in her magic, Celestia climbed off the bed. "Cadence said that The Heart sensed the powerful love between us, as did she, and that it extended these fragments of itself to us, in the hope that we could use them to help make our own part of Equestria a more positive place."

Twilight was stunned silent, her eyes wide as Celestia then knelt beside the bed on one foreleg's knee, the ring levitated in her magic before Twilight. "Who am I to argue with the judgement of the literal Embodiment of Love-magic, and its Herald in the form of Princess Cadance, when I know how true it is?" Celestia paused as she looked up to Twilight, the love for her burning brightly, with that powerful love causing the shard in the ring to glow a brilliant white, before continuing. "Twilight Gleaming Sparkle, Bearer of the Element of Friendship, Princess of Friendship, founder of The School of Friendship, savior and co-savior of Equestria times innumerable, my ex-student, forever mentor and best friend, and finally my broodmare and lover, will you do me, Celestia Solaris, the greatest honor of being my wife, for now and forevermore?"

Twilight could hardly believe what was happening, knowing on some level this would happen eventually, but so completely taken aback by it actually happening right then that she was at a loss for words. "I..." she eventually croaked out, her eyes filling with tears, before her whole visage broke in a huge smile as those happy tears flowed freely down her cheeks. She grabbed Celestia in a tight hug, squeezing the mare she'd always loved to her, "Yes-yes-yes-yes-yes!**" She let out in a flurried expression of pure joy, feeling her now-fiancee's hooves and wings wrapping around her in turn, encasing her in a cocoon of love as she always had ever since she was a little filly.

Neither were sure who started the kiss, both simply finding their lips pressed together in a fiery display of their passion for each other, holding themselves tightly to the other, as though they would die if they separated now. Twilight ended up with Celestia behind her and taking the position of big spoon as she so often did, and was now hungrily kissing all over her ears after breaking the kiss on her lips and moving behind her. Those kisses trailed lower, following her jawline down to her neck, making Twilight give a happy little sigh as she squirmed at her lover's - her fiancee's - affections.

After a short while of enjoying the warmth of her lover's body-heat countering the coolness of the room, unintentionally squirming and grinding her butt into Celestia's underbarrel and sheath, Twilight soon felt something hard and long slide between her hind legs, giving a quiet, happy sigh at the familiar sensation. As she felt Celestia's member slipping between her stifles, she nodded her permission softly, feeling another series of kisses on her neck as Celestia started to slowly grind her erection between her mare's lower lips. Twilight, meanwhile, enjoyed the sensations of being cuddled, kissed, and feeling Celestia hotdogging between her pussylips at the same time, all the while surrounded by her warmth.

Getting her mare's permission with another nod from her after a brief pause, Celestia kept slowly sliding along her mare’s pussy, between her teats, and along the lower curve of her pregnant swell, getting a small squirm or sound of pleasure when her medial ring passed over Twilight's clitoral hood. She felt her mare getting wetter with each slide, until each was slick and smooth with her arousal and Celestia's precum. She meanwhile held Twilight close to her, hugging her from behind and softly rubbing her twin-swollen womb as her hips did their instinctive motions, feeling Twilight's own hips squirming to emphasize her humping.

Many minutes of grinding against each other later, and giving a soft kiss on her fiance's neck, Celestia saw and felt her nod again. Grabbing an ear in her mouth and softly biting it, getting a quiet gasp and wink of the clit against her mare-arousal covered shaft, Celestia pulled her hips back, before Twilight soon felt her large flare press to her lower lips, as always astounded how her semi-flared tip was almost as big as her entire vulva. "So excited that you're flaring already?" Twilight teased, hearing and feeling the soft rumbling of Celestia's chuckle against her back.

"What can I say? I guess you're just too sexy for me." Celestia said in response, feeling her lover wink on her flare, giving an aroused little whinny in return, "Are you ready for me, my love?" Getting a soft nod, Celestia started to push her hips forward.

Twilight just smiled to herself, feeling a hint of pride that she was so attractive to her lover to have such an effect on her; that she was so desired by her carnally that the elder mare couldn't restrain herself. With Celestia kissing her neck again, Twilight felt rising pressure on her slick, swollen vulva, giving desirous little whimpers, until finally Celestia's swelling flare entered her. She gasped softly as she felt full in that so familiar and welcome way, feeling her mare's cock enter her and push deeper, hearing a soft groan from Celestia as she once more penetrated her mare.

Twilight felt a pleasant buzzing in both her head and her loins as Celestia slid ever deeper into her, slowly though this time, inch by inch, centimeter by centimeter. When she hilted nearly a full minute later, flare pressed softly to her cervix, though very cautious about how much pressure she put on it, Twilight sensed Celestia's cock twitching slowly inside her as both took in the sensations the other's body was giving them. Twilight savored being so filled up by her mate, feeling so wonderfully stretched inside by her girth and length, Celestia's body partially encasing her in warmth and love.

Celestia, meanwhile, felt her lover's slick, warm passage gently squeezing her as she remained still inside her, save for the soft twitches of her stallionhood. Rubbing over Twilight’s occupied womb and feeling their unborn foals squirming within her, and more-so the memories of how they'd gotten there quite resembling the present, only turned her on even more. "I love you so much...my wife-to-be." Celestia said in a soft, breathy tone, her cheek pressed and rubbing against Twilight's as she started to pull out.

"I love you too, my wife-to-be..." Twilight replied, with the same loving, breathy tone as Celestia had used, feeling her partner pulling out from her almost all the way, only to slowly slip into her again. While most of the times they had sex since getting together were rough, loud, and fast, not unlike their first night together - usually with Celestia's balls slapping her flank, plenty of moaning, and more than a few wet, slick, or squishy sounds - that didn't seem appropriate this time, with Twilight just accepting her proposal. This time, Celestia made love to her mare instead of outright fucking and breeding her, keeping the pace slow, making sure they both were enjoying each other's body completely.

Celestia kept gently kissing along Twilight's neck as she slowly mated her mare, enjoying each slide along her slick, ribbed marehood, or squeeze from her powerful inner muscles. The slow pace was easily keeping her need to cum at bay, if always slowly rising, the pleasure of having sex with the closest pony in the world to her impossible to ignore. To that end, she also focused more on Twilight's pleasure instead of her own, pulling out to her slowly-bloating flare and easing back in to the hilt each time, slowing to grind her ring over Twilight's clit when she reached it, and earning a squirm, soft gasp, or moan each time she did.

Time had no meaning as the two lovers shared their bodies for the first time as an engaged couple, their love burning hotter than ever now that they'd dedicated themselves to one another. Neither noticed how brightly the shards of the Crystal Heart glowed within their boxes, not realizing how much power their love for each other provided to them, and nor the pleasant, emotional energy they felt now radiating off the stones, except how much it was boosting the experience they were having even more.

Quite some time later, Celestia only slowly humping her mare, the two decided a position change was in order. Without a word, both mares moved so Twilight was on her back beneath Celestia, their crotches somehow never parting throughout the whole transition. The moment they could, they met their lips together in a soft, loving kiss, able to feel the passion the other felt for them through it, able to see the love and lust they held for their soulmate as they gazed into their other half's eyes while they made love.

It could have been hours as they ground and humped, though more likely just many minutes, Celestia's muscles starting to burn from just how long they'd been going at it without rest. They'd kiss sometimes, but more often they'd just look into the other's eyes and rub their muzzles together, cerise and violet pools meeting, both ponies getting lost in them and the pleasure they brought each other.

"I really hope at least one of our foals gets your eyes. They're so beautiful, it'd be a shame if they didn't." Celestia whispered, kissing each of Twilight's eyelids then cheeks, getting a little giggle from her.

"And I hope the other one gets yours, my beautiful stud," Twilight replied, rubbing noses with her lover.

"I'm sorry, love, but I'm getting really close, and a bit tired." Celestia said a few minutes later, even the slow pace finally taking its toll. Twilight could feel the truth in her words as her flare was once more swelling, her pace growing ragged, uneven. She could tell she was on the brink.

"Yeah, go ahead and fill me up, my love! I wanna feel it; all your hot, sticky cum deep inside me..." Twilight replied, giving a little sexy smile. "...let's see how much you put in me this time. I'm betting on a lot."

A few seconds later, unable to take any more stimulation from her broodmare's perfect passage, or her enticing words, Celestia's thrusts stopped as she hilted once more. Knowing what was coming, and only a moment later, Twilight felt the familiar growing of her flare reaching its maximum size and her whole cock twitching rapidly, followed by the warmth of her mate’s cum filling her again. She loved that feeling more than she'd ever admit, and made sure to squeeze down her muscles on the cumming stallionhood each time it twitched, accepting each burst of Celestia's virility into herself, feeling it splashing against her deepest depths.

Pulse after pulse of virile semen were spent into Twilight's marehood, and each made pleasure rock through Celestia, causing her to softly tremble at how very good it felt to cum in her broodmare again. It was a gentle but very deep pleasure this time from how long she'd taken to reach her climax, nothing like the explosive, if more shallow, orgasms she had with faster sex, and one she hadn't experienced in a very long time. This was something special. Her orgasm lasted much longer too, the pleasure even lingering after she'd stopped pulsing her load into her mare, even after she'd passed the dry pulses, before finally drifting into a very pleasant afterglow as she stayed flared deep within her mare.

Twilight, meanwhile, enjoyed the sensations of being cum inside of again, enjoying the feeling of bringing her long-time friend, short-time lover, and now lifelong mate, such pleasure even if she hadn't been set over herself yet. That wasn't to say it hadn't felt good, feeling Celestia's climax inside her, nor the sex that preceded it. Besides, she knew there was plenty of time for her own pleasure later, after all. There always was, as Celestia wouldn't stop until she was fully satisfied; whether by her tongue, magic, or cock, she would never leave her mare hanging.

For then, though, they simply held each other as Celestia's cum drooled from Twilight's pussy and onto both of them and the mattress, her member eventually retreating from her as she grew too soft to stay inside anymore and Twilight rolled over to face her, but Celestia's exit wasn't really noticed by either as they were once more kissing passionately.

"Thank you so much Twilight, for everything. You're the best lover, and wife, that anypony could ever hope for." Celestia softly whispered after time immeasurable of simply cuddling and kissing, cupping Twilight's cheek in her hoof, seeing the small, happy smile she held.

"And you're the perfect mare and stallion for me," Twilight replied, caressing Celestia's back as she hugged her close.

It wasn't long before Twilight felt that familiar hardness between her legs again, sliding between her semen-covered mons. "I still owe you an orgasm, don't I?" Celestia said with a chuckle, before pulling her hips back and lining up again.

"Or several. After all, tonight's a night of celebration, my fiancee."

"That it is, my fiancee. That it is."

Celestia met her lips with Twilight as she once more slid inside her willing mate, and got right to work satisfying her soulmate with a hard, hilting thrust this time.

After another few orgasms between them, their bed and hind ends once more covered in their orgasmic emissions, Celestia again took the big spoon position behind Twilight, her hooves wrapped around her chest and a pristine white wing draped protectively over her broodmare and lover's pregnant belly. As they slept peacefully together, both held a smile on their face, for they were now one, body and soul, and they would prove so at their marriage ceremony soon enough. The Crystal Heart fragments had been glowing white the whole time too, a further testament to the magnitude of their love.

Author's Note

* - side to side, not butt to butt in this case.
** - OG Twilight reference. :3