Big Mac and Rainbow got dressed in warm clothing before heading out one winter day – donning hats, coats and scarves to combat the chill of a Ponyville winter. After bundling up and getting various necessities, the couple headed to Ponyville hospital in order to fulfill an appointment, with both smiling warmly and somewhat jittery thanks to their eagerness to reach their destination.

"So..." Rainbow started excitedly as they walked along Mane Street, trying to stoke Big Mac's curiosity; "What do you think it'll be?"

"Ah told ya, Ah dun wanna know what it is 'til ya have it." Big Mac retorted somewhat sharply. Despite Rainbow and Apple Bloom's eagerness to learn the foal's gender, Big Mac was strongly adverse to it – instead wanting to observe the Apple tradition of not learning a foal's gender before birth.

Last month, Big Mac had adamantly stated not wanting to learn their foal's gender every time the subject of learning it early was mentioned, eventually escalating to a full–on argument between Rainbow and Big Mac one evening. Deciding not to upset her stallion or his values again over such a silly thing,

Rainbow had then reluctantly had given in and agreed to wait – much to her and Apple Bloom's disappointment...but that didn't stop her from trying to change Big Mac's mind. "I know, I know, you want it to be a secret...but don't you even want to guess?" Rainbow kept subtly prying, still thinking in the back of her mind she could convince him to learn whether they were having a filly or a colt.

"Eenope." Big Mac stated bluntly, straight–faced and clearly not budging on the matter – his mind was set, and he was very stubborn when it came to old family traditions.

"Eh, fine, I didn't really want to know anyways..." Rainbow stated in a disappointed tone, putting on puppy–eyes and a duck–lip as she decided to try one last time.

"Good." Big Mac said flatly, clearly unfazed by her act and opening the glass door for Rainbow. Rainbow looked up in mild surprise to find that they'd arrived at the hospital in seemingly no time, the streets of Ponyville mostly clear given the cold weather and forecast of snow soon. Nodding her thanks to Big Mac for holding the door for her, Rainbow headed inside the hospital and was very soon after followed in by Big Mac. The door automatically shut behind them as the winds picked up slightly more, a few snowflakes now dancing in the chilling wind.

~

After checking in and being escorted to an examination room, Big Mac and Rainbow waited for their turn to be seen. After a number of rather uneventful minutes, Rainbow went over to the desk and snatched one of the seemingly hundreds of gloves from a nearby box before laying down on the examination table. Big Mac smiled in minor amusement as he watched her blow it up and produce an impromptu balloon, grinning now at her foalish behavior and deciding to play along. He reached over to pick up a nearby marker in his mouth, nudging her with it after she'd tied the glove's opening closed, not-so-subtly suggesting she draw something on it. Rainbow smiled as she saw Big Mac so eager to play along with her, then accepted the marker with her mouth and unintentionally made her lips briefly touch his.

Both looked at each other as Big Mac dropped the marker and instead suddenly pressed his lips against Rainbow's. taking her quite by surprise and making her let out a startled squeak from the sudden kiss as her wings flared up on reflex. Big Mac smiled against her muzzle as he continued to take the initiative, kissing only softly against her as his hoof found its way behind her head and started playing with the soft hair of her mane.

Rainbow pushed back roughly into the kiss after she'd recovered from the suddenness of it, enjoying the feeling of his mouth on hers as well as the feeling of his hoof now rubbing her neck. "Mac..." Rainbow softly said through the pleasure of the massage after she'd broken the kiss, intending to tell him to stop given their public location. Instead she pressed her head back harder into his hoof as she found her mouth unable to form the words, the message making her scalp lightly tingle, her her definitely not want this to stop given they hadn't been very intimate for a while.

Rainbow softly moaned as Big Mac's hoof trailed down from her neck to her wing, starting to trace along the leading edge of her right wing now as he still kissed her, it flicking in response. Shortly after, his hoof had moved down to the wrist of her wing and started rubbing softly against it. Rainbow couldn't contain a soft moan as she felt his touch on her sensitive wing after so long without it, feeling small bursts of pleasure going through her as she once again met the lips of her stallion.

As Rainbow felt Big Mac's hoof stop rubbing and felt the sudden absence of his lips against hers, Rainbow looked after him with disbelief as he went and sat down. She wondered why he'd stopped everything and just sat back down – and then saw he was smirking at her, apparently thinking he could just hang her out to dry after getting her all worked up!

Rainbow didn't like that. Rainbow didn't like that one bit.

Before he knew what happened, Big Mac suddenly found himself being slammed onto the examination table with Rainbow leaning over him, her muzzle pressing roughly into his as she forced her way into his. He later asked Rainbow how the hay she'd done all that, but she was just as clueless as he was.

"So Mr. Sugarcube, you think you can start me up and then just walk away? I don't think so!" Rainbow said in a pseudo–aggressive tone, making Big Mac fold his ears back and put on a mock expression of fear. It would have almost convinced her if he didn't immediately burst out with a smile and a snort, destroying any effect his act could have had on her. Deciding to change the game, Rainbow asked in an imitation of the lead doctor's voice; "So Mr. Apple, What seems to be the problem?"

"Ah ain't got no problems, doc. Jus' here fer a checkup." Big Mac responded with a giggle, deciding to play along.

"Well, it looks like we have a little bit of inflammation and swelling here..." Rainbow said as she brought her hoof to his semi–erect penis, Mac apparently just as worked up as she was. "...should I see if I can get that to go away?" Rainbow asked seductively as she softly rubbed her hoof once against his sheath, getting a light buck of his hips in response. "Ooh, somepony wants it after all, huh?!" she asked as she then started to consistently rub on his sheath, making his member start peek out more.

"Rainbow...Ah don't think...Ah mean we shouldn't..." Big Mac stuttered as he grew harder still under his mare's trained touch, Rainbow's hoof softly working against his fully–hard shaft now and doing a quite good job of pleasing him already. His voice was a quite trepidatious as light pulses of pleasure started to fire off from his groin, muddling his speech and making Rainbow grin as she saw her stallion's pleasured distress.

"What?! Are you saying we...shouldn't be doing this in public?!" Rainbow said with mock surprise, finishing Mac's sentence for him with a shocked expression followed by a wanton grin. "What, you mean like all those times we "shouldn't have" at our spot at the farm, out in the open where your family could see us? Or in the barn when Applejack was working just the next field over? Or how 'bout that "we shouldn't have" that one time in that alley during my heat, with only a couple cardboard boxes hiding us from anypony walking by? You can't tell me the risk of being caught didn't add to it!" Rainbow said with a tone of pure lust, rubbing harder on his member now as Big Mac's head pressed into the headrest on the bed.

Rainbow remembered back to that time a few months back as she currently teased her stallion's rod, remembering the wonderful time they'd had in that alley...

~ ~ ~ ~ ~

"Mac...we really shouldn't be doing this..." Rainbow said halfheartedly as they entered the nearly empty dead-end alleyway. She noticed a few huge cardboard boxes stacked near the center of the large path were the only thing in the alley other than them, the alley uncommonly used but for storage.

Rainbow's heat had been kicking in hard on a random basis, but she and Big Mac had needed to go into town for...some reason – a reason that eluded her now as her snatch winked in need behind her, her hormones kicking in as she felt an intense burst of heat deep inside her vagina again. So deep that only a stallion could put it out. Her stallion.

Big Mac noticed very shortly after Rainbow did that her heat was kicking in again as her slit got wet, making it glisten in the sunlight and catching his eye, her clit starting a slow pattern of winks as her tail had flagged. He had almost immediately after guided her into the nearby alley as his shaft started to harden when he caught her scent moments after, feeling lucky that the street was nearly abandoned given the time of year as his member quickly reached full length.

"What was that for?" Rainbow asked as she was somewhat roughly shoved into the alleyway.

"Well, we can't be seen in public like THIS!" Big Mac stated in a harsh whisper as he guided Dash behind the improvised wall of cardboard, then indicated his full hard–on and Rainbow's wet and now-swollen snatch on full display.

"Well, the only way this is ending is if we both get satisfied. So what do you propose? That we...just throw all care to the wind and rut right here in this alley?" Rainbow asked sarcastically – only to be surprised when Big Mac went around to her rear and took a deep whiff of her crotch.

"Eeyup." Big Mac said flatly as he then suddenly mounted her, making Rainbow gasp at the unexpected weight and rubbing of his chest on her croup, not anticipating the tight grip his forehooves had around her sides as he started to softly hump against her, his member seeking her needing hole.

"Really?! In public?!" Rainbow asked Big Mac in total shock, almost telling him to get off – but her worries were soon after dispelled as she felt him enter her, Big Mac having found her swollen mound quickly with a lucky thrust and sinking in halfway at once. He quickly buried himself in her to the hilt, making Rainbow groan in pleasure at her need being fulfilled so fully and so suddenly as she felt him spread her so wide, stretching and rubbing her aching inner muscles, sending swells of pleasure rolling through her.

Big Mac almost immediately started to pound into Rainbow hard – taking himself almost completely out of her, only to thrust back in fully a second later and hilt her. The fact that they were doing this in public not only made him want to rut her fast and finish soon. but with it also adding an element of risk to the act that made him turned on beyond all belief.

Rainbow was panting hard as she was bred roughly, her insides being rubbed so perfectly and pleasure racing through her as her eyes constantly darted around the alley – always expecting to see somepony else in there with them but with it never actually coming to pass. She was worried about being caught for sure, but that kinda made the whole thing that much more hot – the risk of somepony seeing them rutting adding an edge to her pleasure she'd never gotten before.

When Rainbow soon after noticed Big Mac's head lowered down next to hers in his pleasure, she reached her muzzle over and impulsively grabbed his ear between her front teeth and bit down softly. She didn't know how he would react, but she trusted her instincts and started to gently nibble on her stallion's ear, rubbing her incisors under the soft hair and directly against his skin.

The reaction to Rainbow grabbing his ear was immediate; Big Mac's thrusting into Rainbow became erratic as he felt Rainbow start to suddenly but gently bite and scrape her teeth on his ear, her actions causing an additional wave of unexpected and intense pleasure to overlap the already powerful pleasure he was receiving from her tight, grasping passage on his member.

Big Mac felt his climax drawing close...but so soon?! The pulses of pleasure from his member and the tingling across his scalp from her nibbling on his ear was setting him to the brink sooner than ever before. He didn't know why such a simple action from Rainbow was having such an effect on him and undermining his ingrained Earth pony endurance, but what he did know is that he couldn't last long if she kept it up...yet it felt WAY too good to ask her to stop.

The sensations of Rainbow’s passage constantly rippling along Big Mac's length and her teeth scraping and softly gnawing his ear, along with her sexy little moans of pleasure directly into it, pushed Big Mac closer to the edge with each thrust. With a loud grunt, and only a couple of minutes into their breeding, he finally pushed himself as deep as he could go as he felt his balls twitch and then tighten against his body, his tail flagging, and his penis soon after starting to flare, heralding his orgasm's inevitability. As he felt Rainbow started to rhythmically squeeze around him in seeming reaction, he knew she was very close too, making him glad he wouldn't leave her unsatisfied.

As his pleasure reached its peak with Rainbow overstimulating him at two places, Big Mac finally felt himself pass the breaking point as his glans flared fully inside Rainbow and he felt the pressure in his pelvis snap, followed by his body sending the first of many loads up his length. He heard a deep moan released directly into his ear from his mare, the sound welcoming in his orgasm as well telling him of Rainbow's – the final apple breaking the cart

As Rainbow felt Big Mac's head flare deeper than ever before inside her, she knew what was next and felt herself tip over the edge as well with a deep moan. Both came together perfectly simultaneous for the first time ever, with each greeting their orgasm at the exact second the other had. Big Mac started pumping his love juice into her for the second time that day, his member buried deep inside her and his flared head keeping a tight seal against Rainbow’s womb as he pumped load after load of his thick, sticky stallion milk directly into her fertile core.

Rainbow milked Big Mac of each shot of his foal–batter as her tunnel squeezed more out with every contraction, her body working hard to drain him dry and get everything she could from him as she ground her hips up against him, trying desperately to get him as deep as possible during their climax. She felt Big Mac filling what must have been her very womb this time, the fullness and warmth of his seed so deep inside her belly making her orgasm swell to new heights as he started to hump very deeply now, grasping her tighter and pressing his still gushing head against Rainbow's cervix with each hilting. Each rough thrust into her forced a muffled cry out, Rainbow's pleasure taken even higher with each shot of his virile seed into her inmost depths.

When both finally came off some of the strongest orgasms they'd ever had quite a while later, Rainbow's belly was swollen slightly with just how much seed Big Mac had put into her, his flared head not letting any escape and making the massive gushes only able to enter her womb – with Big Mac also having majorly over–produced thanks to Rainbow's over-stimulation on his ear and the fact they were doing this in public working him up more.

Big Mac hesitantly pulled out and dismounted Rainbow after a taking a couple of minutes to recover from his own intense orgasm, a stream of his excess seed quickly making its way down to the ground from her well-overfilled passage as his still-partially-flared head popped out from her canal. They both simply stood there for a while as Rainbow drained onto the alley ground and Mac watched, amazed at just how much he'd cum and filled her.

"Mac..." Rainbow barely managed to pant out after letting go of his ear, making the stallion look from her white-painted and still-draining rear to her face to her in dazed attention; "...how exactly did you think filling me up with like a gallon of your spunk and making me leak it everywhere would make us less conspicuous?"

"Uh...sorry?"

"Don't say sorry..." Rainbow said as she raised her tail to him, her cum-covered clit winking to him, "...push that cum right back where it belongs!"

Big Mac only smirked as he mounted her again, eagerly getting on to round two.

~ ~ ~ ~ ~

In present times, Big Mac couldn't argue with Rainbow as she rubbed his penis just the right way, the pleasure it caused skewing his judgment. Judging by all the other ponies waiting in the other hospital rooms, it would likely be quite a while before the doctor could see them anyhow, right? Might as well have some fun in the meantime!

"Alright Rainbow, but jus' be quick 'bout it!" Big Mac finally said as he felt his mare's tongue teasing his glans now, agreeing as he was unable to contain his pent-up need any longer. "We dun need t' get caught after all!"

Rainbow was indeed quite swift about it, taking half his rod into her maw in one downward movement. Big Mac pressed his head back hard into the headrest, barely containing a deep moan as explosions of pleasure traced his spine. Rainbow was giving him his first public blowjob and he had to admit the risk made it that much better, this being some of the most intense pleasure he'd ever gotten from just her mouth!

Rainbow had started to softly bob deeper on Big Mac's member, now inviting him into her throat. He kept an eye on the door, making sure to keep an ear out for the sound of approaching hoofsteps or any other sign anypony was coming. He had to admit, though, he wasn't so sure he'd want Rainbow to stop even if they were interrupted!

Her juices started to trail down her legs as Rainbow continued to work on Big Mac's rod, swallowing occasionally on his deeply–buried stallionhood now and getting a deep, quiet moan from him in response. Rainbow reached the hoof she didn't have on the bed for balance down to her crotch and started rubbing her wet snatch, gasping softly at the first contact.

Big Mac's pleasure skyrocketed at her throat's contractions, his breeding rod constantly throbbing in Rainbow's throat now as she took him deep, forcing his eyes closed and his muzzle towards the ceiling as pleasure overtook his awareness. Rainbow meanwhile played with her slightly-puffy lips for a bit – them having gotten a bit more engorged and sensitive since she had gotten pregnant – then moaning softly as she moved lower and her hooftip found her clit.

As she upped her pace of bobbing on Big Mac's rod again, she quickened her own work, rubbing into her passage deeply with the wet, squishing sounds of her suckling on Big Mac turning her on even more. The wet sounds of her own self-pleasing and the soft, sweet moans she'd let out occasionally ramped up Big Mac's arousal as well, making him start to thrust lightly and meet her every drop on him half-way.

~

The door was slightly cracked now, a pair of eyes getting the perfect view from behind as this mare rubbed herself and apparently deep–throated the stallion she'd come in with! Wait, was taht Rainbow Dash?!

~

It all came to a head a very short while later, with Big Mac unable to hold out as the very risky situation set him to the edge far sooner than normal. Barely containing his grunts and moans as Rainbow expertly worked his member, she nearly made him nearly cry out every time she'd hit that oh-so-sensitive spot she knew he loved licked with just the tip of her tongue.

Rainbow felt Big Mac's throbs increase with her own clenches around her hoof as she rubbed herself deep, her lips spread further as she plunged her hoof constantly deeper into her marehood. When she hit her clit roughly one last time, she came on the spot, pleasure making her whole body tingle and her legs feel like jelly, the orgasm almost feeling as good as when Big Mac did this for her.

Rainbow couldn't contain a full moan escaping her throat as she came, milking her hoof as extreme pleasure surged throughout her and her release steadily dripped to the floor, her clit winking towards the door. As he noticed his mare's efforts on his member increase – as well as caught the scent of her release – Big Mac couldn't help but let out a moan of his own as his member started to flare, Rainbow's now-aggressive sucking and clenching on his member finally bringing him to the very brink.

With one final swallow, Rainbow finally set Big Mac over the edge, his head fully flaring now as she felt the first shot of his hot pent-up seed shoot down her throat, followed quickly by many more substantial gushes. Big Mac couldn't help but hump up somewhat roughly on instinct, trying to get deeper into the warm squeezing of her muzzle and throat, though she was already totally bottomed out on him.

As their intense mutual orgasms died down a matter of moments later, Rainbow pulled off of Big Mac's now-wilting member and panted for air, having kept him down her throat during his entire orgasm once more.

~

The door to the room silently closed now, the voyeur apparently having seen enough as both the mare and stallion in the room came off their orgasms, quite aroused and set over by the mare's pussy winking right at them as she came, with that only adding to the whole situation. They just hoped nopony visited the broom closet for any reason...

~

When they heard voices nearing the room, both Big Mac and Rainbow quickly got into less compromising positions, with Big Mac quickly grabbing a nearby newspaper and sitting down, opening it and using it to cover his still-semi-erect member. Rainbow meanwhile got up onto the examination table and grabbed a nearby box, cleaning herself to get the worst of her mess off of her crotch and hooves before throwing the wadded tissues into the trash can. As she noticed the small puddle she'd left on the floor, she could only hope the doctor wouldn't notice it...or Celestia–forbid it step in it!

"So how is our mother–to–be today?" a sudden voice asked as the door opened, startling both ponies as they quickly moved to look more natural. The doctor felt a minor blush form on his face as he realized what he'd apparently walked into; two blushing ponies looking at him with wide eyes and the scent of sex still hanging heavy in the air.

Deciding to ignore the scent as best as he could, the doctor then got to business. "So, you're here for the 'endo–uterine' spell to view the foal and check its health, correct?" he asked, turning to Rainbow. Both she and Big Mac nodded, still slightly flushed from their previous activities during the wait to be seen. "Ok, shall we get to it then?" the doctor asked, still slightly distracted by the scent so prevalent in the room. Rainbow nodded and the doctor's horn starting to glow as he approached Rainbow, then pressed his horn to her lower abdomen as an image of her innards formed in his mind.

After the spell had given him a mental image of Rainbow's womb and its contents moments later, the doctor's face showed mild surprise as his magic fizzled out, clearly seeing something unusual but not bad. "Did you want to know the gender? If not, I can blot out those portions before I project it." the doctor asked, looking to both parents.

Rainbow gave Big Mac one more pleading look, but it went unnoticed and unheeded. "Eenope." said Big Mac with finality, with Rainbow sighing and nodding her approval of his decision.

"Alrighty then." the doctor said, smiling at knowing how surprised they would soon be as his horn lit up once again, a beam to the wall appearing as he projected the image to a nearby projector screen.

A perfectly accurate internal view of Rainbow's womb and of the two very tiny foals inside was seen on the screen, both Big Mac and Rainbow herself shocked and marveled at the two small forms. They were only about a few inches long each and still very early in development, but Rainbow and Mac could already see the small hooves forming on the ends of each their four legs, their small rounded muzzles and tiny ears also clearly visible. On one, they saw small wings beginning to form on its back – indicating clearly it was a Pegasus just like Rainbow. The other seemed to lack both a horn and wings, showing it would likely be an Earth Pony like its father.

Both parents felt an intense pride as they looked on at the projection, both smiling widely as they finally saw in full saw what they had created together. "Twins?!" both Rainbow and Mac nearly shouted in surprise, clearly not expecting to be blessed with such a rarity. Twins were rather uncommon among ponies, with single-births being the norm. For Pete's sake, the latest twins in Ponyville were Pound and Pumpkin Cake, and they were born a few years ago!

Rainbow felt tears of joy forming in her eyes, and couldn't help but nuzzle against Big Mac, feeling a wetness on his cheek as well. They had created these beautiful children together, and she could only imagine how overjoyed she would be when she could finally hold them in her arms. Big Mac put his hoof over Rainbow's as he looked into her tear–glazed yet still–beautiful eyes with his own wet eyes, then soon after nuzzled against her muzzle as they shared the moment together.

Rainbow smiled as she felt Big Mac's muzzle against hers, then felt him resting his head on her soon after. Both looked at the fruit of their love still displayed on the screen, and knew they could do nothing but patiently wait as their foals still prepared to come into the world many months later – to be welcomed into it with their open arms as mother and father.

Rainbow and Big Mac were then advised by the doctor to get more clothing and such in anticipation of the two foals' arrival, and to prepare themselves mentally as well. Two foals were twice as much work as one after all – double the feeding, double the diaper changes...double everything! Both couldn't help but feel nervous in anticipation of the responsibility of two foals, but they had faith in each other and knew together they could do anything.

"Well, the foals look like they're perfectly healthy and are developing normally for this stage of pregnancy!" the doctor stated happily after studying the projection, getting smiles in return from Big Mac and Rainbow at the good news.

Suddenly, Big Mac remembered a question he and Rainbow had wanted to ask. "Hey...uh...Doc?"

The doctor had ended the projection now and looked to Big Mac, waiting for him to continue.

"So...uh...Rainbow 'n' Ah were wonderin' iffin it'd be safe to...uh...t' have..." Big Mac felt a blush forming, unable to form the final word of his question as his tongue got tied up on it.

Rainbow rolled her eyes at Big Mac's shyness on the subject, and said what he couldn't flatly – "He wants to know if it's safe for us to have vaginal sex while I'm pregnant."

Big Mac nearly climbed the wall he was so embarrassed at Rainbow's bluntness, but the doctor seemed unfazed – after all, he got questions like this on a daily basis. "Well, you can easily have intercourse during the first two trimesters of pregnancy, but the third may prove a bit more...difficult to manage, especially with twins. However, you can likely safely have intercourse right up until you're foaling, though whether or not it's physically possible is another story." The doctor explained. As an afterthought, he asked – "Mrs. Apple, Would you like me to do a basic pelvic exam just to make sure there are no risks?"

Rainbow nodded, the doctor shortly after approaching her rear.

~

After checking Rainbow fully and giving her the all-clear, the doctor confirmed to both she and Big Mac that it would be safe for her to have sex as long as he didn't go too deep and rupture the cervical plug, that they didn't put too much pressure on her belly during, and as long as nothing happened during or after sex that would be cause for alarm. He explained that minor uterine contractions were normal during and after a mare's orgasm in addition to the vaginal ones, but warned that if stronger contractions developed during or after sex during the second or third trimester, then they needed to get to the hospital immediately.

Big Mac and Rainbow left the hospital a short while later quite happy, not only knowing their twins were perfectly healthy and developing properly but also that they could safely be more intimate than simple oral!

Author's Note

Another chapter! Yay!

This chapter took quite a bit of research to get down pat. Also if anypony's wondering, their foal is about 100 days into development. Only about 220~240 more days til baby!

As a side note, I based the "can have sex during pregnancy" and various other things during that portion on HUMAN facts. Horses don't have sex merely for pleasure IRL, so don't hold it to me if it ain't true! :P