As autumn in Ponyville rolled around, the weather started to cool and the ponies started to get out their warmer clothing, preparing for the colder months ahead. Rainbow Dash woke late one morning and discovered something she hadn’t experienced since she was a filly – her bed was wet.

Rainbow sighed as she got up, feeling a sticky wetness on her backside and stifles. She took her Stetson off the nearby hat–rack and plopped it on her head, this becoming a daily routine of hers ever since Big Mac had given it to her. She then smiled as she remembered her dream, the dream about her and Big Mac spending a day at the park a few days past leaving her in a pleasant mood. The vibes slightly faded as she remembered she’d wet the bed, but she shrugged it off. The bed was easy enough to clean up, after all.

Then Rainbow sneezed. Then twice more. “Ugh.” she groaned out, quickly heading to the bathroom as a headache started to develop.

As she had last night, Rainbow had started staying at the Apple residence more and her house less, having found one day that an additional bed had been set up for her in Big Mac's room. She had been ecstatic that she had been accepted into the family already, and had immediately taken advantage of being able to sleep in the same room as her coltfriend as often as possible.

Rainbow proceeded to stumble towards the bathroom and went pee. She sniffed hard, trying to clear her stuffy nose as she determined she'd recently contracted Hay Fever and the symptoms were just starting to show. She groaned as she felt her body aching slightly, light–headed as she reached for a tissue to blow her runny, stuffed–up nose.

When she finished her business, Rainbow then cleaned her rear, noticing an odd viscosity to the fluid – but she merely shrugged that off as she started running the bath water, her mind too congested to really care about such minor details. All she could think of was Big Mac as she bathed, the warm water helping to relax her unusually tense muscles. She decided she'd have to give him a visit out in the fields today.

~ ~ ~ ~ ~

Big Macintosh and Rainbow both had decided to allow their relationship to be known of now, deciding on it the day after their previous…unpleasant event, in which both misunderstood the other’s feelings on a matter. They went places together and did activities of all sorts – and whether it be the Ponyville Rodeo or a simple visit to the park, Rainbow Dash always wore the Stetson hat he’d given her the night of that event, it never leaving her head but for bathing and sleeping.

The hat had been adjusted to fit Rainbow’s head now; she had taken it to the House of Hats with Big Mac’s blessing and had it modified to fit her properly, with it no longer sliding over her eyes whenever she tried to wear it. Her original asking to modify the hat caused Big Mac to pout slightly at how cute it looked when it slipped down onto her muzzle, but Rainbow Dash teased back that it must have been cute too when she’d tripped over a chair in the Apple’s home when it had covered her eyes while walking, broke the living–room table and bumped her front–left knee in the process. Big Mac thereafter gave her his full blessing to have the hat modified to avoid repeat incidents, not wanting his Dashie to get hurt again…nor any more furniture for that matter.

The two had also recently revealed their relationship to the immediate Apple family, Rainbow Dash’s family and the other three of her best friends that didn’t already know. Applejack already knew, having helped them with the aforementioned event, had respected their wishes to keep their relationship secret until they were ready to tell others. However when the two went to tell Twilight about them being a couple, figuring she’d be as surprised and happy for them as the three other had been, she had already been waiting with a congratulations gift.

Twilight had levitated the very sloppily–wrapped present to them and with a giggle had admitted to being very bad at using wrapping paper. After the present had landed in front of them and they thanked her in advance, both tore into the paper together – and inside the wrapping paper lay the book on pressure points and massage techniques that both had borrowed.

At being found out in such a way, this caused both Mac and Rainbow to blush hotly as Twilight winked at them, with her then wishing their relationship well and, with a smirk, hoped the knowledge they gleaned from the book would help them in their more 'personal times'. That remark caused both of their blushes to deepen further and their muzzles to start sinking to the floor in embarrassment, Twilight holding her mischievous smirk the whole while.

~ ~ ~ ~ ~

After her bath, Dashie decided she needed to clean the mess she made on her bed...but first she went pee again. She pulled her still–wet sheets off the bed, threw them into the washer, then added in the soap while it filled with water. As she closed and started the load, she noticed some of the fluid had gotten on her hoof. She looked at it and then rubbed it between her hooves, the fluid being clear but slightly cloudy, seemed thicker and slipperier than urine…yet her foggy mind couldn't tell the significance of the difference.

Rainbow rinsed her hooves off and proceeded on her day off work, then heading outside to find Big Mac and to hang out with him as she’d earlier planned. As Rainbow traveled down the main road to the fields, she noticed the normally cool fall day was unnaturally hot to her – beads of sweat rolling down her face while she slowly flew low to the ground, expending barely any effort at all. "Dang hay fever!" she moaned out, quickly wiping her drippy muzzle on her forehoof.

Arriving at the fields a few minutes later, Rainbow headed out into the east orchard where Big Mac had told her he’d be working all this week. She felt the moderate breeze flow through her hair and feathers as she took flight again after resting a moment, sighing in relief as it cooled the sweat that had formed on her during her short flight there. Why the hay was she so hot during autumn? Rainbow wondered as she suddenly felt the familiar pressure as her bladder tightened up again, soon after heading to the outhouse to relieve herself again.

...and why the hay did she need to pee so much?!

As she spotted Big Mac’s large red form bucking a tree to get some loose leaves and branches off a couple minutes later, Rainbow smiled as she spotted her love. She quickly closed the distance between them, making him turn to her at the familiar sound of her flapping wings. She’d come to visit him during work more often now that their relationship was out in the open and he loved that she did – not only was it nice to have her company while out in the fields, she was also very helpful sometimes. She would often help him with his work, especially if the current task was up high and would have normally required him to go get the stepladder from the storage barn. This was one such time.

“Hey, Dashie!” Big Mac yelled out, waving his hoof at her as she quickly approached him. Once in range, she landed and folded her wings in before wrapping her hoof around her stallion's neck and brought him into a kiss and he did the same in kind. When they broke it, Big Mac looked into Rainbow's beautiful cerise–pink eyes and asked; “Ah know this is sudden and y’ just got here, but Ah could really use yer help. Y’see them dead branches up high there? Would y‘ mind gettin’ ‘em down fer me?”

Rainbow Dash smiled and nodded to Mac, accepting the task as she always did. Despite her minor aches everywhere, she flapped her wings and hovered up to the point Big Mac had pointed out. With a few tugs and snaps the dead branches soon fell to the ground, landing nearly perfectly at Big Mac’s hooves as he bent down to retrieve them. Her task complete, Rainbow smiled as she lowered herself to the ground and folded her wings again, always happy when she could help her coltfriend, even if only in small ways like this.

Rainbow helped Big Mac with various other tasks throughout the day, all while keeping close to him. Very close. More often than not, Big Mac felt his Dashie rub on him, whether it be a nuzzle against him, her side against his, or even a quick kiss on his face or muzzle. Big Mac didn’t mind it at all however and generally nuzzled back or turned his head to smile at her, getting a contented sigh or sometimes even another quick kiss from his filly-friend. Boy-howdy she’s affectionate today, Mac thought. Wonder what’s gotten into her?

When the clock tower soon after sent forth its five gongs a few hours later, Big Mac sighed happily as his work day ended and his personal time begun. He nodded to the south and Dashie knew exactly what he meant, her smile increasing in size as she flapped her wings excitedly at the prospect of spending time with him personally, unusually giddy to spend time with him.

As they traveled to the south field and shortly after arrived at their special field of grass, the winds shifted towards Big Mac. As he breathed in the next time, he got a good whiff of Rainbow Dash as the wind blew her scent right into his face. Mac almost gagged at the musky scent and instantly felt his penis drop and start to harden as a result of her pheromones. “Uh…Dashie?” Big Mac said as his mind started to fog over with instinctive lust – “Didjya know yer…in season?”

Dashie was completely oblivious to the meaning of what Big Mac had said, never having heard that phrase before. She chuckled before teasing him – “I’m 'in season'? Well duh! We’re both in a season, Mac! It’s called ‘autumn’!”

Big Mac shook his head in frustration, getting irritated at her misunderstanding as he continued to harden and his cloud of lust continued brewing – “NO! Ah ain't kiddin' 'round. What Ah meant to say is tha' y’all are in heat!”

The realization slammed into Rainbow Dash like a runaway carriage; she was always a late bloomer when it came to estrus. While most mares started going into their heats in the middle of spring and summer, her body always waited until the end of spring and beginning of autumn before starting its cycles. The wetness on her bed as she dreamt about Big Mac, her unusually tense muscles, her being hot despite it being cool and windy, the close attraction she felt to Big Mac today and the giddiness she felt being around him, having to pee so often… they were all signs of her heat that she'd missed!

Rainbow sniffed again as she realized her nasal congestion had prevented her from smelling her heat, also making her contribute all the other symptoms of her fever, with it never actually dawning on her that it was about time for her cycle to start again. She blushed deeply as she realized that she had just come to Mac in full–blown estrus, as a mare coming to her coltfriend while in estrus is generally strongly discouraged in pony social etiquette unless it was planned beforehand, lest any...unwanted complications arise. This left Rainbow not even able to imagine what Mac must be thinking of her right now.

As Rainbow Dash felt her blush increase at her predicament, she could just barely smell the fairly–strong masculine scent coming from Big Mac – starting feel the familiar dull burning sensation start in between her legs and a slight itch forming as well, her body detecting the pheromones from Big Mac and starting to ready itself for him. She now knew that she was definitely in heat as it was started to hit her hard now that she had a stallion's pheromones flowing through her; her skin getting hyper–sensitive and making the cool breeze feel freezing to her now as her whole body started to heat slightly more, her rear lips starting to swell and getting wet as she felt the usually passive urge to breed come to the front of her mind, demanding her attention. Demanding to be sated by that stallion.

Big Mac observed these changes in Dashie, getting a perfect view of her swelling and moistening vulva with her facing away from him, her tail to the side and giving him a good view. Big Mac felt his now–fully–hard member slap against his underside involuntarily and found he was suddenly fighting a losing battle against his instincts as he approached her rear and sniffed deep. He instantly felt light–headed as her pheromones assaulted his mind again, her softly musky scent making his head feel light and making him just want to jump on her back, then rut her until he was sure she was properly taken care of.

Big Mac's conscious mind finally forced its way back into control just as he placed a hoof on Rainbow's haunches, making her look back at him in subdued surprise even as her tail flipped aside and flagged over her back on reflex to his touch on her rump. When an eager whicker escaped her at the sensation of his hoof on her croup, he watched her eyes expand in surprise, apparently neither having expected quite that kind of reaction! Big Mac felt a blush starting to form on his face as he realized what he’d started to do and removed his hoof from her rear, instead forcing himself to back away from her and sit down, causing his hard–on to stick out tall and proud from between his rear legs.

Rainbow Dash quickly noticed the sight of the breeding rod between Big Mac's legs, feeling a sudden burst of heat from her rear end as her eyes locked on it, her tail now flicking rapidly. She wanted it. She needed it. Inside her. Now. Rainbow shook her head as she came back to her senses, now realizing she was almost on top of Big Mac – her eyes still locked on his pride and joy and apparently it was now his turn to give her a look of surprise. Finally managing to pry her eyes away from his penis, Rainbow met Big Mac's eyes instead – and in them, she read a barely–subdued lust, totally sure he could read the same in hers.

“So…uh…” Rainbow managed to stutter out, rubbing the back of her head with a hoof as her eyes once more locked onto Big Mac's length, rewarded by a visible throb for the attention she gave it. She felt so torn at the moment, her instincts demanding she breed with her love, but she herself was so personally unsure of if she was ready for this or not. She asked herself – was she really ready to have a foal? Was she really ready to start a family with him and take their relationship down such a serious and irreversible path?

Big Mac stood up, his rock–hard dong swinging side–to–side as he walked over to Rainbow Dash’s now sitting form and sat next to her. His soft, masculine odor wafted again into her nose, making her instincts strengthen their grip on her as she leaned over and rubbed her muzzle against his. They just sat there for a minute with their hormones torturing them, trying to decide what to do until Big Mac finally spoke up – “We don’t have t’ if yer not ready.” Big Mac was fighting the urge to just push her over on her back and have at her, barely containing the animal lust her heat had brought out in him – but his stubbornness and morals let him prevail over instinct.

Rainbow Dash was still deep in thought, although her breeding instincts were making it rather hard to think with such an attractive and virile stallion sitting right next to her, still deciding whether or not she should just leave and get a heat–suppressing potion from Zecora or have Twilight cast that anti–estrus spell when she felt a soft pair of lips on hers. She pressed back against them on reflex, her increased sensitivity making it feel like heaven as she felt Big Mac's tongue press against her teeth. Mac's tongue met no resistance as it moved past them and into her mouth, with him quickly finding her tongue with his own and causing her to moan at the sensation.

Their desperate kiss didn’t break for a number of minutes, Rainbow and Mac's lust relieving itself if only slightly as they started to grind against each other while their tongues sparred, their pheromone–induced over–sensitivity amplifying every touch. When they finally did break the kiss with a huge exhalation from both, Big Mac ran his hoof through Rainbow's trademark prismatic mane then brushed aside a strand that had fallen across her face. He looked into her eyes and her into his as they felt a closeness like they’d never felt before.

“Mac? Are you sure I'm…we're ready for this?” Rainbow asked, but was only answered with another soft peck on her lips. “Well, I guess you are!” she exclaimed, managing a nervous chuckle despite the tense situation. Rainbow sighed as she felt her hesitations finally crumble, her hormones and love for him making it almost impossible to resist anymore. She needed him inside her.

“Buck it, take me!” Rainbow said suddenly, then rose to her hooves and turned around, flagging her tail up high and giving Big Mac a good look at her soaked and puffy treasure as she winked it at him. It was such a primitive gesture, but she knew it would show her need for him better than any words ever could, the most simple but effective way of a mare telling her stallion of choice 'I need you, come breed me'.

Big Mac whickered as he approached her; tempted to just jump on Rainbow's back, rut her hard, blow his load in her and give her body the foal it so wanted, but he somehow managed to restrain himself even after she’d invited him to take her. Instead of mounting her, Mac approached her rear and pressed his tongue against the swollen flesh of her vulva, making Rainbow gasp and start to lightly buck her hips against him, the sudden warmth and wetness on her over–sensitive marehood as his tongue lapped over her plump lower lips sending a significant burst of pleasure throughout her. Big Mac continued to lick her for quite some time, feeling his member throb with each few licks as he inhaled her lightly musky scent constantly, that aroma of her need making his lust burn hot as Celestia’s sun as he continued to work her up.

Big Mac continued to lick Rainbow's swollen lips for a few moments more, occasionally seeing and feeling her wink against his tongue as he continued to resist the instinct to rut her, wanting to please her as much as possible before that now–inevitable act. Rainbow meanwhile was panting hard, pleasure amplified by their hormones coursing through her veins as she felt Big Mac’s tongue finally press inside her. She gasped harder for air, feeling like she was on the edge of climax the whole time as he started to wriggle it around in her for a couple more nerve–wracking minutes, pleasing his mare to the best of his hampered ability.

It wasn't long after the two-minute mark that Big Mac's tongue found that magic spot inside her, with that finally all his mare could take. Rainbow cried out as she came hard, her passage milking Mac's tongue as she was almost blinded by her pleasure, her vision blurring as that wonderful orgasm shot through every nerve ending and made her whole body tingle, feeling her clit constantly winking against his lower muzzle, her hips rocking against him in her throes of climax.

As she came off her orgasm, she realized that instead of helping her heat it had only made the burning need inside her increase to an almost intolerable level, making her whine out her need as she became desperate now and literally begged to be bred – "Mac, for Celestia's sake mount me already! Please!"

Big Mac licked up what he could of Rainbow's burst of release and felt most of the warm fluid land on his muzzle and face, her unique flavor and constant winking throughout somehow managing to ramp his lust up even further. Finally, he could take no more as he heard her beg for him, then lifting himself up as he again placed his hoof on her rump, preparing to mount his mare. Big Mac gave Rainbow one final warning, barely able to given his lust–filled state of mind. “Y’all sure yer ready Dashie, 'cuz once Ah start, Ah ain’t sure I can stop ‘til…Ahm done.”

Rainbow knew exactly what he meant and couldn't want anything more at the moment then to feel him on her back and inside her, satiating the burning she knew only a stallion could. “Oh for...I wouldn't have it any other way, OK?! Now please Mac, make this burning end already!” Rainbow nearly shouted as she removed her hat and hung it on a low–hanging tree branch, to which Big Mac backed away and quickly unlatched then removed his yoke with his other hoof, throwing it carelessly onto the nearby grass. Rainbow then winked herself a couple times at her stallion, hoping to get him to finally rut her already with such an obvious and primal invitation.

Big Mac saw Rainbow's invitation and barely resisted the urge to simply lunge at her and pin her to the ground as he took her needing body as his own, instead feeling his rod slap against his underbelly again as he replaced his hoof and pressed on Rainbow's rear. He shortly after moved himself up and mounted her, now quietly whinnying deeper and more aggressively, his breeding whinnies nearly turning to growls as he slipped his hooves down to grip her sides tightly and made her sigh at the welcomed pressure of his chest rubbing against her haunches.

As Mac started to roughly thrust against her rear, looking for his instinctive target as he blindly sought it, he felt Rainbow shift her hips to help his search for the warm and winking hole that had earlier invited him. He heard her whickering herself as she spread her legs wider and gave him a slightly bigger target on reflex at that sensation, her partially–pinned tail flicking against his chest as she impatiently waited for him to enter her, with Mac's deep breeding whinnies turning her on beyond belief.

After a few moments of his pre–cum being smeared all over her rear and eager anticipation from both as he slowly neared her waiting hole, Big Mac felt the heat radiating off of his mark as he finally pressed his rod against Rainbow's swollen and needing vulva. After but a second of gentle pressure on her outer lips, he felt himself slip inside of her...and suddenly he was in heaven.

Both gasped as Mac slipped the head of his penis in between Rainbow's lips, sliding into her very easily due to just how worked up she was. Rainbow then felt him push in deeper, feeling every inch as he slowly pressed into her and stretched her wide, making firecrackers of pleasure explode throughout her and a moan escape her as she was entered her first time.

Rainbow felt...full. So very full, like Mac was stuffing her entire body with himself somehow, filling her in a way she'd always needed during her heats but never knew how much. "Ooooooh...! M–Mac. S–so fuuuuuull!" Rainbow moaned out, throwing her head back at the feeling of every bump and vein in his length as her body gripped him tightly within her, her passage overjoyed at finally having something to squeeze against in her time of need.

The heat and tightness of Rainbow's insides almost made the inexperienced Big Mac blow his load in her right then but he resisted, knowing he needed to put Rainbow before himself and let her needs come before his own no matter what his instincts told him. Big Mac gave another hard thrust – and unwittingly, instantly punched through a barrier. He heard Rainbow whine but not in pleasure, and as his cloud of lust faded from that whine, Big Mac looked up and saw her looking back at him with her face showing slight pain not unlike when he'd first seen her in the orchard.

Both were silent for a moment, Rainbow recovering from the sudden minor pain inside her and Mac from the shock of having hurt his mare, even if only slightly. How could he have been so stupid as to forget Rainbow was a virgin, he wondered, that she'd never before been penetrated. "Ah...Ahm sorry fer bein' too rough Dashie." Big Mac said as he nuzzled her neck softly, feeling Rainbow lightly trembling beneath him, whether from pleasure or not he was unsure.

"I–I'm...OK." Rainbow said calmly with a hint of surprise. The pain was there, but very mild and nowhere near what she was expecting – not much worse then a minor wing cramp, just inside her belly instead. "It hurts just a bit. Just...gimme a second." Rainbow asked as she looked back to Big Mac, seeing him nod. Big Mac did as asked and remained stark still on top of her even as he felt Rainbow reflexively rippling and squeezing around him, not wanting to hurt her even though his body was urging him to rut her hard.

After only a few seconds Rainbow nodded, telling Mac he could proceed. After having been unintentionally teased, he eagerly did so – shortly after burying himself fully in her, his next slow thrust causing a loud moan of pleasure from Rainbow as the last few inches of his twelve–inch–long breeding rod took their rightful place in her love tunnel. He was perfectly nestled within her and spreading her whole passage wide now as both shared their first time, together in bliss as they lost their virginity to each other.

Both took a moment more to recover from the initial penetration, with Rainbow contracting and relaxing around Big Mac's hilted cock as she adjusted to his girth and Big Mac holding still and feeling his orgasm recede back as the urge to cum so soon diminished slightly. After the short break, Big Mac pulled out of Rainbow slowly and pressed back in half–way, causing both to moan at the sensation.

After a few more slow single thrusts, Big Mac let his instincts guide him as he instead began a steady pattern of shallowly thrusting in and out of Rainbow, each slow entry and removal causing a burst of pleasure for both as their breathing increased to panting. Their ears picked up the soft squelching as his breeding rod moved in and out, in and out of her dripping–wet slit, the sounds of their lower union stimulating them that much more as Big Mac started softly kissing Rainbow's withers, getting a pleased sigh and gentle tremble from her as a result.

Rainbow Dash cried out especially loudly when she felt Mac's medial ring finally press again into her passage as he started to thrust deeper, it stretching her open just a little wider and hitting her love button as he pressed in just right. The sensation of his ring rubbing her most sensitive of areas made Rainbow cry out and flap her wings at her sides as pleasure once again caused her mind to blank, overtaken again as her passage started clenching.

With this orgasm, however, Rainbow felt even more intense pleasure then her first as she now had something inside her to squeeze around during her climax. "OH CELESTIA! I–I'm cumming!" Rainbow cried out, unable to contain herself as she felt so good, so...complete with Big Mac inside her.

While Rainbow came again with a cry and a whimper, the sudden clenching and milking on her stallion’s cock almost made Big Mac climax again. His resolve to put her first prevailed however and he barely managed to stave off his orgasm during hers, teetering dangerously on the edge of his release the whole time as he felt her passage tightly spasm around him. He came especially close to losing control again when he felt the wet warmth of her release against his balls, stimulating him that much more and again almost sending his load into Rainbow prematurely.

Big Mac started to softly thrust into Rainbow again as the clenching of her passage reduced to gentle ripples on him, feeling his own urge to finish lessened as her squeezing decreased. He started humping gently but deeply into Rainbow throughout her afterglow and earned soft, ragged moans of pleasure from her as his member once again massaged and soothed her burning core – her body's needs lessened just from him being inside her, but still feeling that burning for that final relief. "M–Mac you're...you're so awesome! I love you so much!" Rainbow whined out as he slid into her again, hilting her once more and filling her oh-so-full of himself.

Moments after, Big Mac increased the pace of their breeding slightly more much to Rainbow’s delight, making her pant and moan deeply as her head lulled back at his thrusts and eventually met his muzzle in another kiss as he continued to satisfy her. Rainbow kissed her stallion roughly for a short while until the need to breathe overtook their passion, both panting hard as Rainbow finally broke it and let out a yelp when a sharp spike of pleasure suddenly rolled through her, Big Mac once again rubbing against that most sensitive of spots inside her. "Oh Maaaac..." was all Rainbow could manage to moan out, intense waves of pleasure nearly crippling her ability to do anything but stand and be taken by him.

Big Mac kept his moderate pace for a good while longer until Rainbow shouted out her final demand, needing the ultimate gift from her stallion now. “Rut me like a stallion should, Mac!” she cried out in her passion, swiftly feeling as Big Mac tightened his forehooves around her sides in response.

After Rainbow stated her need for him to finish for her, Big Mac let his haunches hump into her of their own accord, feeling his cock starting to wildly throb in her as he let his breeding instinct fully take over.

Mac's now–short–and–deep humps caused Rainbow to almost scream at the intensity of pleasure she got from the increased pace and stimulation, her next orgasm welling up quickly as she was now being properly rutted by her stallion, her instincts screaming for his seed.

Big Mac felt a familiar tightening in his pelvis and throbbing in his balls, barely managing to shout a final warning through his cloud of pleasure. “I’mma cum soon! Y’ want me to pull out?!”

“If you pull out, I’ll never forgive you for it!” Rainbow screamed back in her lust, wanting to feel what she knew was soon to come. Wanting to feel her stallion give her the ultimate satisfaction she never knew she needed.

As Big Mac made his final rough thrusts into Rainbow's begging body, he finally couldn’t hold himself back anymore, feeling his tail starting to flag up and down as his pulses grew ever stronger and his head started to flare.

As he finally clenched his haunches tight and with one final deep hump into his mare, Big Mac let out a guttural groan as he felt his glans flare fully. He felt Rainbow's walls squeeze tighter around him as his head swelled up greatly within her, soon after feeling the first stream of his seed shoot deep into her, with it giving an audible splurt as it shot out.

Mac loosed a deep moan of pleasure as he stayed as deep as possible within her, clenching her stifles tighter against his as many more ropes of his semen followed the first – painting Rainbow's fertile innards a creamy white as the sticky life–giving substance coated them and feeling an unbelievably strong surge of pleasure. An instinctive sense of accomplishment rolled through him, wave after wave of pleasure washing over him as he started to fill his fertile mare with what would undoubtedly give her his foal.

Rainbow felt Mac's flared head spread her inmost walls so much wider, followed by a pause as he hilted himself as far as he could into her. She could feel him pulse – once, twice, three times– and then she felt it. She felt a powerful throb from his member, then a burst of warmth deep inside her as he throbbed and throbbed again within her, each jerk of his penis loosing another burst of that soothing balm into her.

Rainbow then felt the force of Mac's thrusts against her sensitive walls as he started to roughly thrust into her, instinctively hilting himself inside her with each entry as his flared head pressed his seed as deep as possible into her. The feeling of his cum going so far inside her satisfied her very deeply on a wholly new level, making her feel like letting him breed her was definitely the right choice.

The creamy, soothing warmth of her stallion's cum being pumped into her once, twice, thrice and so many times more relaxed Rainbow's breeding instincts further even as she felt herself tense up and peak once more. With the filling, calming feeling growing evermore in her belly and spreading deeper, Rainbow's passage started to milk Big Mac's spurting rod on reflex as another nerve–wracking wave of orgasmic pleasure flooded through her, her third climax hitting her very hard as she arched her back up against Mac and felt him slide just a little deeper as a result.

Big Mac felt Rainbow's chasm start to contract around him and her vulva wink against him as she came for her third time, Rainbow whinnying her passion out as she pressed and sealed her hips tightly to his and splashed her cum against his inner stifles and balls. Big Mac felt the most intense sensations to date as she massaged him so roughly inside her while he came, his vision flashing white with each shot of his seed into his clenching mare. Surges of pleasure beyond anything he'd ever before felt overwhelmed him and making his back legs wobble, making his breathing turn to ragged pants as he made Rainbow truly his.

Mac felt each pulse of his cum leave him as Rainbow milked it out of him, feeling each one pass through him and into her – and after a while felt the sticky warmth of his own seed washing back against his flared head. Apparently she was full. After a while, his semen and her fluids started to leak past his flared head with each thrust, the excess escaping from her even as he pumped more still into her overfilled body. He felt Rainbow get more slippery with each thrust into her, each one easier than the last as he felt his leaking cum lube her more, letting him hump deeper and get his new squirts further into her.

Each of Rainbow's squeezes was met with a twitch from Big Mac's deeply–embedded cock and another, now smaller pulse of warmth so deep inside her now, making her feel fuller and fuller as she felt her entire tract being coated by his seed – her whole body now feeling warm and tingly and oh so wonderful. As Rainbow felt the last few small spurts leave Big Mac and enter her, she sighed contently when she felt the burning and itchiness of her heat mostly gone.

Rainbow shuddered in relief as the unpleasant feelings of earlier were instead replaced by the large soothing mass of Mac's seed now resting in her belly, making every inch of her inner sanctum feel warm, sticky and slightly tingly. Oh and full – very, very full. Both started to relax as they came off their orgasms and their tensed muscles slowly loosened after their releases, both shuddering occasionally when she'd squeeze him or he'd dry–pulse in her, the actions making their over–stimulated minds release just one more bolt of pleasure through them.

Big Mac didn’t pull out of Rainbow just yet, neither wanting to break this union, both instead lowering their upper halves simultaneously as their rumps remained in the air, his hips still pressed firmly against hers as his stallionhood remained fully flared deep inside of her. Words had no place as they rested like that, kissing softly or cuddling until both felt his soft member slip out some minutes later, Rainbow feeling a shudder as a dollop then a stream of his seed escaped her.

"W–wow." Was all Rainbow could stutter out, her word being met with a muzzle affectionately rubbing against hers and a similarly quiet "Eeyup." Both she and Mac rested for a short while more, panting and cuddling more while their afterglows set in. Soon after they engaged their lips and tongues in another sparring match, showing their love and appreciation to each other.

~ ~ ~ ~ ~

Applejack gasped as she pressed her hoof hard into her sopping wet baby passage, pleasure wracking her hard as she rubbed her sensitive insides while spying on the couple in the grass fields. She watched as Big Mac’s head snapped back and heard their faintly audible cries and words of pleasure as he came in Rainbow – and as she heard their release, Applejack suddenly realized he was most likely pumping a foal into her, judging by the very obvious scent of a mare–in–heat she'd earlier smelled at the house. She herself wasn't in heat, she'd earlier checked that Apple Bloom still hadn't had her first heat yet, and Granny Smith was much too old – so that only left one pony.

At the thought of her brother knocking up one of her best friends, Applejack let out a loud moan as she felt a stream of drool running down her chin and neck, tensing up as her pleasure met its climax. Her strongest orgasm of the year took her over as her snatch clenched down hard on her hoof all while still watching her brother and his mare–friend breed, continuing to grind herself hard against her hoof as she came hard.

Applejack's pleasure was long faded and she was well into her afterglow as she saw Big Mac slip out of Rainbow some minutes later – but when Applejack saw a big dollop of his seed escape Rainbow's well–stretched hole and into the grass below them, she started to rub anew on her slit as she felt her lust rising again at the sight. "Wow big bro, ya filled her up good!" she whispered as she kept rubbing herself, imagining what it must feel like to be so full of a stallion's cream in her own heat, making her pregnant too.

~ ~ ~ ~ ~

As the winds shifted a number of minutes later and Big Mac caught the scent of Rainbow’s heat again, his cock soon after stood at full attention despite him so recently breeding her. Rainbow grimaced slightly as she stood up, her wings flared up in arousal as she again lifted her tail and winked her vulva at him – both inviting him to take her again and causing another small dollop of his seed to escape her and land in the grass.

"Please," Rainbow begged loudly, swaying her rear to emphasize her need – "I need more, please! My heat's starting up again!" Rainbow hated to beg, her pride being too great to let such come to pass often, but this was an exception! She felt her heat welling up again – and although it was a dimmer flame then before she'd been bred the first time, it was swiftly rising in intensity.

Rainbow needed her stallion more. Now.

Big Mac nodded as he stood up and gave Rainbow's mound a teasing lick, tasting his seed mixed with her release as he tried to turn her on even further. In the end, he got only an annoyed groan from Rainbow Dash as well as a soft buck from one of her rear hooves against his foreleg – not hard enough to hurt, but definitely hard enough to get his attention and tell him to stop teasing. "Put it in already!" she whined, swaying her rump and winking herself at him again, trying to get him to mount her already!

Big Mac decided to give Rainbow what he knew both she and he truly wanted, moving closer to her and putting his hoof on her croup. He mounted and penetrated Rainbow again in one swift move, leaning over her as he started to hump deep into her passage, his and her previous ejaculations making him slip in and out of her very easily. Rainbow cried out in pleasure as he penetrated and started to buck her in one fell swoop, her inner muscles clenching down hard on her stallion as he thrust into her hot passage, again and again, each thrust quelling her once–rising heat a little more every time he entered her.

As Big Mac felt his over–sensitive stallionhood being gripped by Rainbow's very warm, velveteen walls once more, he continued to thrust deeply but slowly into her, the pace much softer and much more loving as the urge to rut and be rutted was lessened by their first releases. He was careful to always slow down when his medial ring met Rainbow's lips on the way in – to slowly press into her and be rewarded with a gasp of pleasure from Rainbow as he prolonged its passage over her clitoris, himself also groaning as he felt his sensitive ring enter her tight cove.

Big Mac soon started to rub his muzzle against the base of Rainbow's wings, causing her pleasure to spike and lessen rapidly as he pressed into and nibbled on that point as he bred her again, giving her a double whammy of pleasure as she now panted through his ministrations – her head afloat in the clouds of ecstasy only he could bring her.

Big Mac kept the slow pace for what felt like an eternity for both and Rainbow felt her passage constantly squeezing around him as his cock occasionally throbbed in her, causing a jolt of pleasure to flow through both of them each time either happened. When his head passed over her G–spot again Rainbow shuddered hard, her pleasure spiking almost unbearably high for a moment.

Mac thrust a few more times against that sensitive spot when he'd noticed her reaction, making Rainbow start to tremble as the pleasure became almost too much to handle, causing her bite onto the grass in front of her and take a mouthful. She started chewing the greenery to help her cope with the almost orgasmic pleasure that was making every muscle tense up, her entire body shuddering constantly beneath her wonderful stallion.

It wasn’t long until Big Mac felt the tightness in his pelvis again, heralding his climax. He stopped nibbling Rainbow's wings as he instead increased his grip on her sides and lowered his head beside her at the sensation, humping into her hard for the last of their second breeding as he finally let his instincts take over again as he felt a familiar snap in his pelvis.

Big Mac then pressed his stifles flush against Rainbow's and tensed up as he felt his glans flare again, once again feeling her passage grow tighter around him as he swelled in her – ensuring she'd take all he had to give once more. Big Mac very shortly after started cumming inside his mare again with a deep groan, all but mentally checking out and letting instinct guide him as he continued to hump deep into Rainbow, giving her innermost walls and womb a fresh coat of white.

Rainbow felt Big Mac's cock twitch, twitch, twitch in her as he pressed himself very deep in her again and soon after another hard throb as his new cum squirt into her, then be pressed deeper still as he humped into her, his loads being somewhat fewer and thinner than the first batch but just as warm and filling! As she felt that deeply satisfyingly warm fullness shoot deep inside her again, Rainbow cried out as another intense orgasm overtook her, her cry of pleasure meeting and merging with Big Mac's to make a discordant melody of their passion.

Rainbow milked his member again as it pumped and pounded the final remnants of his virile load deep into her, with each of Mac's pulses met with a firm squeeze of her own. Rainbow's passage was trying to pull his seed deeper into her to where it belonged and into her already–filled womb, but instead the few bursts he shot into her instantly backwashed out, Rainbow's belly already totally filled by their first time.

~ ~ ~ ~ ~

Applejack had just cleaned herself up from her first two orgasms when she saw Big Mac once again mount Rainbow and couldn't help it as she started to rub herself again, watching the two breed for the second time. “Y–y’ give it to her h–hard b–mmmmh–big brother! M–make her a mama.” she moaned out as she watched them from the storage barn, matching their slow pace as she rubbed herself.

A long while later Applejack watched Big Mac press his hips against Rainbow's and snap his head back a second time, continuing to hump into her as his cry of passion and hers were barely audible from that distance, Big Mac undoubtedly seeding his fertile mare again.

As she heard them cum again, Applejack bucked her crotch up into her hoof as she finally let another powerful orgasm overtake her, having held out and kept herself on the edge so she could cum with them – finally feeling her pussy clamping down on her hoof as she gasped and trembled through the strong pleasure. Her powerful orgasm was interrupted however by a very familiar little voice – “What’re ya’ doin’, sis?” it asked, making Applejack’s eyes shrink to the size of pinheads as she looked up and saw her little sister Apple Bloom leaning over the hayloft above, her eyes wide and her mouth agape with a heavy blush on her face.

“Uhhhhh…” stammered Applejack, feeling a blush form on her face – unaware of her actions as she continued to instinctively grind on her hoof, still riding out her orgasm while trying to think of a response. “Ahm...uhhhhh...jus’ havin’ aaaaa a li’l’ mmm–fun?”

Apple Bloom gave Applejack a knowing look and suddenly gave a cute little moan as her own face contorted in pleasure. Applejack felt a drop of viscous liquid land on her shoulder as what could only be Apple Bloom’s release dripped through the floorboards, the light squishing sounds from above barely audible as Applebloom apparently reached her own climax. She realized that Apple Bloom had clearly been spying alongside her, apparently just finishing herself off as well. Apple Bloom gave a nervous chuckle and confirmed Applejack's thoughts – “Dun worry, Ah was watchin' 'em too. They’re such a cute...'n' sexy...couple.”

Applejack and Apple Bloom watched as Big Mac pulled out of Rainbow a second time, then watched as they lay down and kissed. "Such a cute couple..." Applejack agreed with a smile, then started to clean herself up.

"Eeyup," said Apple Bloom in a mock of Big Mac's voice, causing Applejack to giggle as the two sisters cleaned themselves up after their shared voyeurism.

~ ~ ~ ~ ~

Their lust completely sated for now, both Big Mac and Rainbow collapsed to the ground in exhaustion after he'd pulled out, embracing each other and kissing in their afterglows. Soon after hearing seven gongs from the Ponyville clock–tower, both of their eyes widened when they realized they’d been rutting for over two hours. Big Mac started to get up but was stopped by a gentle hoof on his side. He looked back and was greeted by the lips of Rainbow Dash against his again, as well as the hoof on his side soon after wrapping itself around his shoulders and followed shortly by her wing.

“Thank you, Mac. I love you so much.” Rainbow whispered into Big Mac's ear, pulling him closer to her with her wing at his back.

Big Mac felt his eyes start to well up as he responded. “Ah love you too, my little Dashie.” He nuzzled against her after their kiss ended, loving the feel of her soft hair against his, the softness and warmth of his mare against him as she held him close.

After getting a long drink of water and using the outhouse, Rainbow and Mac lay with each other and cuddled as they watched the sun setting, always a routine of theirs after they pleasured each other. As the moon started to rise, Big Mac and Rainbow Dash soon after got up and headed to the main barn, intending on showering and cleaning up the caked–on residue of their lovemaking.

They shared the shower, kissing and rubbing against one–another as they washed themselves and each other. When they got to their naughty bits, they’d decided to "help each other" and had gone a little slower, rubbing a little rougher and eliciting soft moans from each other as they softly stimulated and cleaned each other's genitals. As Mac had started cleaning Rainbow's crotch, he caught a whiff of her heat again, making his member drop as her pheromones once more worked their magic on him – urging him to mount and seed her once more.

When he couldn't take it anymore, Big Mac once again mounted Rainbow as their lust burned hot again from the teasing, Rainbow's heat once again flaring up. Mac started to take Rainbow again, roughly thrusting into her as the warm water sprayed over them, the warmth of the water and the sensation of it washing over their skin overstimulating them as Big Mac once again begun to assault Rainbow's foal-passage with rapid, deep humps. Both clenched their teeth at the sensations this most recent rutting brought from their still over–sensitive genitals, their bodies buzzing with slight pain and extreme pleasure as they bred once more.

Rainbow moaned out softly but constantly, unsuccessfully trying to keep herself quiet and not disturb the other family members sleeping in the house. As she felt him once again hit her 'special spot' however, she couldn't help but let loose a deep moan, feeling herself shudder again despite the warm water washing over them, pleasure bolting through her and making her quake at its intensity.

Big Mac wasn't able to hold out very long at all this time; the hot, tight clenching of Rainbow's insides and the constant pelting of warm water on his back set his mind on overload. As he humped a few more times into her, he felt his mare start to tremble again as he started to flare in her, the further spreading it caused next to her deepest barrier seemingly enough to set her off again.

Big Mac felt Rainbow shudder hard again and let loose a whimper as he felt her passage hold his member tight and massage it roughly, keeping him inside her until she'd milked him dry once more. The tight squeezing of her passage on him caused a small amount of pain to mix with his pleasure, her muscles crushing his sensitive penis in a vise-grip as he then felt himself start to twitch and shoot into her again, more powerful surges of the pain-pleasure spreading throughout him now as he came into her once more. Big Mac could only give Rainbow two small squirts of watery semen this time, his reserves completely spent now as he finished inside her for the third time within only a couple hours, with the rest of his throbs coming up dry even as her body all but begged him for more.

When Rainbow's orgasm ended moments later, Big Mac pulled out of her again and dismounted with a wet schlick, the very small drizzle of his semen that escaped her quickly washed away by the shower water. She gave a quiet gasp as she felt his hoof against her very sensitive nether, rubbing at the caked–on semen and fluids from their earlier romps, as well as the fresh from just now, as he started to clean her again.

Maybe they'd actually get clean this time instead of Big Mac making more mess inside Rainbow.

A half–hour later, with their bodies dirtied and then cleaned again, Big Mac and Rainbow went to Big Mac’s room. Entering it moments later, they shared another kiss before settling on the mattress, getting close to each other as Big Mac gave her soft kisses on her neck and earned a coo of approval. Big Mac’s eyes suddenly widened as he remembered something very important he needed to do. “Ah'll be right back.” he said as he opened the door and exited the room, leaving a slightly puzzled and more-then-slightly curious Rainbow waiting on the bed.

Well, Big Mac thought as he went downstairs to retrieve what he'd picked up in Ponyville earlier that week, looking inside the box to confirm it was still there – Ah made her my mare in one way today; Ah may as well go all the way with it.

A few moments later, Big Mac arrived back into Rainbow's and his shared room holding a fairly-long red-velvet box in his mouth. As Dashie was laying on the bed, Big Mac knelt down before her and opened the box. Inside was a gold engagement bracelet, a large diamond in the middle and encased with pink tourmaline – with the gems carefully chosen by him to be the same color and radiance as Rainbow's eyes – surrounding it in the shape of a heart.

Rainbow’s eyes instantly watered up at the sight of the object, then started to fall down her cheeks as Big Mac asked her the question she'd wanted to hear since shortly after she'd met him. The one she'd wanted to hear since that first night they'd spent together in the field.

“Rainbow Dash, will you be mah mare and wife?” Mac asked confidently, then eagerly awaiting her response.

Rainbow Dash launched off the bed and wrapped her hooves around Big Mac's neck, instantly crying out “YES!”, her voice quivering with emotion as she accepted him as her stallion without hesitation. He was finally her stallion – all hers to love and hug and be with forever, just as she'd wanted for so many months!

As Big Mac felt the wetness of Rainbow's tears on his shoulder, his own eyes teared up as he felt their bond tighten that much further at her acceptance. At her finally becoming his mare.

After placing the bracelet on her front right hoof, Big Mac and Rainbow Dash shared another kiss – a soft and chaste kiss, but more meaningful then any others they'd ever shared. A kiss now between soul–mates. As they lay on the bed once more and spooned, she fell asleep in his loving embrace, her head against his chest as she heard the steady thu–thump of his heart. Before drifting into the dream realm, Rainbow randomly realized that instead it was their heart now, figuratively speaking of course – the bond of stallion and mare making the two instead forever one.

Author's Note

Here's the chapter everyone's likely been anticipating since the very git-go. Hope you liked the execution, as this one took me an entire day (on and off) to write and initially edit, as well as many, many more hours to fine-tune and improve.

As for future, I have a number more chapters planned. This ain't over for quite a while, so I hope y'all are up for the ride!