Author's Note

First off: Please read the story description if you haven't already. It's there for a reason!

I was new to writing in the erotica department as of this story's creation. If there's something about my story that you dislike (grammatical/story-weaving errors, too repetitive, etc.), I'd really like to know about it in the comments. If you're going to leave a dislike on my story, please at least explain WHY you dislike it. I can't improve on a problem if I don't even know there is one after all!

Prologue: Life Lessons

Pairing(s): Twilight Sparkle(solo)

Contains: Extensive amounts of a character learning about equine reproduction - including textbook-esque depictions of mare and stallion anatomy and equine breeding, textbook descriptions of sex (AKA sex education) and a virgin mare in her first actual estrus getting turned on by it, preceded and followed by female masturbation (hooves/sheets) and lots of squirting and two orgasms.

~ ~ ~

Springtime in Ponyville was quite a beautiful sight one early spring day in Equestria shortly after the annual Winter Wrapup, an event used by the ponies of that town to help bring in Spring. Winter Wrap–Up had gone well this year under Twilight Sparkle's system that had been introduced long ago, and because of its success that first year she'd developed it, it had been used every year since.

As it was so soon after that Spring–bringing event, the world was still adjusting to the new season; the flowers had just started to bloom, colorful birds flew through the sky or started laying eggs and nesting, with everything just coming back to life from its winter slumber.

The ponies too were still adjusting, getting their houses in order after the winter's thaw and packing their winter gear away for the next year.

The mares' bodies were also changing in response to the warmer weather, the longer days and more sunlight exposure brought on by the season change triggering for many mares that most dreaded time of year. The time nearly all mares despised most.

Breeding season.

Estrus cycle.

Fertility.

But for one mare, this time is a mystery to her, but one she's determined to solve. With her and within the Golden Oaks Library is where our story starts.

~ ~ ~

Twilight Sparkle cocked her head at the book she was reading, then looked at her violet-colored rump and back to the book again. She discovered when she was a filly that if she was having a problem, reading up on it was usually a good way to find a remedy, or at least, comfort herself with the knowledge on what the cause was as well as possible ways to quash it. The subject of her interest was sitting in front of her, a book titled ‘A Young Pony's Guide to Sexual Anatomy, Sexuality, and Reproduction in Ponies”, as well as behind her – her rump. She was awake at midnight again just like the previous night, the burning having awoken her from her sleep tonight as well as then.

This had all started yesterday morning when Twilight had developed an ever-present itch and swelling in her “privates”, as well as discovering that she was much more sensitive to the touch 'down there' when she cleaned herself after using the bathroom, and she sometimes would feel something between her legs shift, as though pushing outwards, before going back in, this feeling somewhat...pleasant to do. She also noticed her rate of urination had increased substantially more, with her 'going' nearly twice as often as normal but never able to fully empty her bladder. She had decided to keep herself indoors when she smelled that she’d also started to emanate an odd, musky odor from her backside when this had first come on, the scent being one that she couldn't quite put her hoof on yet somehow smelled so familiar to her…

The feelings weren't exactly painful, merely a constant mild to moderately itchy-burning sensation, but it was really starting to become a nuisance when it woke her up from the intensity spikes! So when she’d awoken from an especially odd dream of her brother Shining Armor getting very 'close' with her and then climbing on top of her for some reason, she'd felt the intense burning in her nether when she awoke from it. She'd then grabbed the first book from the multiple stacks she'd long ago borrowed from the Canterlot Library that she thought would be relevant upon calming down and starting to read for the cause of this...what was it even, a malady?

Another odd symptom of this affliction was that whenever she thought about a stallion or even any male in general including Spike, her genitals started leaking a strange clear and slippery substance, as well as causing the burning within her and the scent emanating from her to intensify for a while...and all she could think of was stallions! She was tired of the burning and was now trying to discover the cause the best way she knew of – studying!

Remembering it suddenly, Twilight stopped reading and glanced over to the scroll Spike had earlier told her was waiting for her with a message from Cheerilee and thought for a moment of reading it. Spike had earlier told her it read that Cheerilee requested Twilight's help with a field trip and the date and time of said field–trip. Twilight made a note to factor that into her next schedule but decided against reading the scroll itself, as Spike had already told her exactly what it said. That and she REALLY wanted to get to the bottom of this problem she was having.

Twilight had planned out being alone tonight, intending to study all night long to find the solution for her newest obsession. She'd sent Spike off on some chores for the day, and in addition to the Bits for the required items, she'd also given him his allowance early. Judging by the extra-long time he'd been gone, he undoubtedly used his allowance to visit Sugar Cube Corner or the local gem shop, both being his regulars when he was given a few extra bits for himself.

Twilight had also found a way to buy herself overnight upon Rarity visiting unannounced and mentioning the Cutie Mark Crusaders would be having a sleepover that night. As soon as Twilight had heard of the planned sleepover, she'd volunteered Spike to spend the night over at the CMC Clubhouse to chaperon over the sleepover, much to Rarity's delight.

Despite quickly noticing the very obvious musky scent of a unicorn mare in heat surrounding Twilight, Rarity had been a lady and hadn't mentioned to her that she was in season. She figured she'd just embarrass the poor dear over the scent she was giving off, with most ponies keeping their heats as private as possible. Rarity quickly dismissed herself a short while after when she felt her own loins getting aroused from Twilight's pheromones, unintentionally leaving behind a small wet spot on the pillow she'd been sitting on.

When Spike later arrived home from his chores – and judging by the gem fragments and frosting around his mouth, his snacking – Twilight had told him what she'd signed him up for. He’d been extremely reluctant as expected, bringing up how much trouble the three fillies usually got in at sleepovers, then about how he didn't want to...but Twilight been very persuasive. After all, she really needed him out of the library for the night...even if it did cost her that large ruby she'd been saving for his birthday.

Now, however, Twilight had the library all to herself all night and intended to use it to discover the cause, and possibly cure, for her unusual symptoms until she'd fallen asleep and was abruptly awoken again by the weird dream and burning.

As she read further into the book’s introduction about the start of puberty in equines, Twilight's thoughts were suddenly brought back to the many, many springs she’d spent with Celestia at the Royal Castle in Canterlot...

~ ~ ~

Twilight had spent the first few weeks of spring, then the last few of summer, with Princess Celestia every year since she was a filly – even after moving to Ponyville from Canterlot. Every spring and summer Princess Celestia would send a scroll to her, then shortly after a carriage to bring her to stay at the castle for a few weeks. She was treated as she always was, but there were a few notable differences; she would never be allowed outside the castle walls during this period, and all the male guards were strangely absent, replaced instead by a large magical barrier that prevented unauthorized entry into or out of the castle.

Whenever she'd complained of an itch or burning 'down there' during her visits, with those sensations starting to occur every year since she’d hit about eleven years old, Princess Celestia had always started having Twilight drink a number of potions every day, with them causing those sensations to become far less intense. She was then given the same potions every day for about a week, then again after the itches and burns came back a couple weeks later, until at long last she was finally allowed to roam the castle grounds freely, her restrictions once again lifted as the male guards returned to their normal posts inside the castle.

Twilight remembered back to a specific, very recent springtime visit, a strange odor being in the air for the whole time she was there, a deep and musky scent that always brought a blush to her cheeks and made between her legs feel funny. She had remembered hearing moans at nighttime; deep, guttural moans that were constant for a number of minutes at a time or sometimes high and feminine, occasionally accompanied by different, deeper moans or growls that sounded almost like a stallion alongside.

Once, she’d even gone to check on the sounds when she became concerned that Princess Luna may have gotten hurt, the volume of the sounds coming from her room rising to a pitch that all of Canterlot must have heard. When Twilight reached her quarters that night, however, she discovered her chamber doors were locked, a blue aura around it telling her that it was magically sealed shut by one of Luna's spells. The small knock she gave on the door was obviously not heard over the constant moans and whinnies, so feeling defeated she had gone back to bed.

When Twilight had asked both the sisters in the morning why there had been moaning and cries the previous night for hours on end, she was just met with an awkward silence as both Celestia and Luna stared at each other for a minute. Celestia then claimed to have slept all night and not heard a thing, but her shifting eyes and fake smile told another story. Luna, however, with a glowing blush, had said she had a "severe itch" she had needed to take care of and that it had taken all night with a "special friend" to scratch it!

This statement elicited a harsh glare from Celestia, causing her to ask Luna to speak in private. That request was swiftly followed by much shouting from the hall by Celestia about how “Twilight wasn’t old enough yet", leaving Twilight completely confused about what she wasn‘t old enough for!

Seeing how upset this event had seemed to make the two princesses, however, especially Celestia, Twilight had never again mentioned the loud moans she'd hear on and off for those days. Her curiosity kept eating at her until she'd finally given up ever learning the cause, accepting it as one of the great mysteries of the universe to her as she eventually moved on to other things.

During her foalhood all the way to only a short while ago, Twilight had always been limited on her reading materials as well, never having been permitted to the wing containing biological texts without being accompanied by Princess Celestia herself. Celestia had told her the ones she'd been rejected to read were 'advanced studies for when she was more mature', and Twilight had never questioned her about them again, always content that Celestia had her best interests at heart with the limitations.

After Twilight had so recently become a Princess, however, Princess Celestia had removed all restrictions she previously imposed on her within the library. She had told her that not only was she allowed to remain in Ponyville all year round, but was also told that she was allowed to check out whatever and however many books or scrolls she wanted, regardless of their content and for as long as she chose, telling her it was a coronation gift.

Twilight had responded very promptly to her coronation gift by visiting the library the next day and checking out nearly the entire Biology wing, much to the librarian’s surprise. Twilight had always been curious about how the entire equine body worked, and now that she could, she intended to find out as much as she could about it.

In present times, she still had the books checked out and sitting around her library, never having time to read as much as she'd wanted to anymore since she’d been assigned her duties as Princess, as well as spending time with all of her Ponyville friends.

~ ~ ~

Twilight cocked her head one way and then back in the other direction, lifting her eyes from the book as she got up and started pacing as she was apt to in times of stress. After a few more minutes of pacing, she'd flopped down on her hindquarters but immediately shot back up as the pressure on her privates gave the burning sensation an unexpected boost, making her cringe until it slowly diminished from the harsh burning that the pressure had caused back down to its normal simmer. “Dang it, I just know the answer to this feeling is in this book!” Twilight commented, stamping her hoof determinedly and then carefully laying back down this time to avoid putting pressure on her swollen backside again.

"While mating seasons are the only times of year for the ponies to successfully breed and bring new foals into the world, all they are to single mares, or those just not wanting a foal, was just a horrible, unstoppable itching and burning ache deep inside their mare-parts for three to seven days," Twilight read, "Alongside with the physical symptoms, intense mental urges to breed come too, and are very hard to resist for some. Each four to seven days of estrus is followed by a cooling–off period of about two weeks, then another heat cycle, until the end of that breeding season in early fall.' Well, that would explain some things..." Twilight said, remembering the times Celestia would keep her in her chambers happened about once a month in spring until autumn, almost like clockwork.

"When estrus come upon a mare, there are only two ways to end the burning of 'full heat' completely, and many less self-controlled mares were all but willing to comply to the easiest one, their breeding instincts strongly manipulating their actions. The easiest, and easily most pleasant, method to end their burning was multiple sessions of unprotected sex with a stallion over the course of the estrus, and likely getting pregnant by him. The other, much harder method to simply endure and wait for it to naturally end within four to seven days."

"Surely there must be another way..." Twilight said, before continuing reading.

"The only other, less permanent options for mares in full heat other than being bred or waiting were using certain potions, herbs, or "physical methods" to dull the unpleasantness temporarily...but even after using any of these, the itch will still be there, omni–present but at least less unbearable for a while. In the next chapter we will discuss the mare reproductive tract, then the stallion's in the following, and finally conception, gestation, and birthing throughout the rest of the book in that order."

As Twilight then finished the introductory pages of the book that she'd before been reading, she was quickly introduced to a very detailed cross-section diagram of a female equine’s whole reproductive tract, as well as the accompanying text.

The outermost part of a mare's anatomy is called the 'vulva', or ‘labia majora’...

“So…” she started, then lay down on her back with her back legs spread, careful to avoid crushing the wings she was still getting used to, feeling a slight blush forming on her cheeks as she looked down her puffy slit despite being totally alone, “…this is my ‘vulva’?”

Twilight proceeded to look again at the diagram in the book now levitating above her, then looking down at her own vulva, barely able to see it given her angle. As she viewed the diagram again, she personally added, "...and past that the rest of the mare's 'privates'”.

Annoyed by being unable to see much of her lower end, as well as feeling a shudder of sensation crawl up her spine as she experimentally poked her puffy and wet lips, Twilight was suddenly struck by an idea. An idea that may not only help her find the cause of her affliction but also to quell a curiosity she’d always had but never had the nerve, knowledge nor resources to pursue.

A personal, hooves–on studying of her own 'privates'.

Twilight levitated the book upstairs with her to her room, the brilliant-raspberry red magic encasing both the closed book and her horn as she dragged it in the air behind her. Upon arriving in her bedroom, she set the book on her dresser and proceeded to use her magic to both move her room's full-sized mirror to the foot of her bed, then close and lock her bedroom door. She’d knew she’d need both the mirror and the privacy to allow her to do what she planned to do next, feeling a blush again developing as she considered the specifics.

She then lay down with her back on her bed, spreading her rear legs wide as she tried to get comfortable, turning on her bed to lay on her stomach moments after first laying down, shifting and sighing at the soft feeling of the clean royal-purple-colored silk sheets beneath her rubbing against her coat. Every part of her more sensitive to the touch since this...whatever it was...started.

When she shifted again while trying to get comfortable her 'privates' rubbed against the silken sheets, causing Twilight to stiffen up at the sudden sensations that simple touch down there had caused. A deep urge developed from that pleasurable sensation, with Twilight feeling a sudden need for more of it.

Twilight shifted her crotch against the soft fabric again experimentally, trying to see if she could get more of those wonderful feelings between her legs again. She was swiftly answered as her swollen mound rubbed the silky sheets again, making her moan softly and sending another burst of pleasure crawling up her spine, confirming her suspicions that rubbing herself down there felt really good! Twilight continued to rub against the sheets softly a few more times, loving the sensation coming from between her legs as she thereafter started to reflexively grind harder against her mattress, making a small wet-spot develop where her flesh met the fabric.

Twilight rubbed her swollen crotch against the silky smooth sheets for about a minute more, feeling that weird moving sensation in her privates happening a lot down there, and each time it did, intensifying the sensations. She found herself unable to stop from grinding against her bed as her hormones and instincts took over, making her moan out louder as her pleasure started to rise. Twilight felt muscles down there starting to clench now, muscles she didn't even know she had before now, as she started drooling on her pillow, her body telling her to continue but her conscious mind feeling somewhat hesitant about it. Why do I feel so compelled to do this she wondered, but then too, when it felt so good, how could it possibly be bad for her?!

When Twilight felt the sensations start to get almost overwhelming and the clenching in her pelvis increase its intensity more, she felt compelled to grind harder against the sheets, soft pants and moans coming constantly from her throat. She felt as her body tensed up now, moaning loudly now as she pressed her face into the pillow to muffle herself, giving her all to the last few hard grinds she gave the mattress.

Finally, it all came to a head as she spread herself and rubbed the inside of her 'vulva' on the smooth fabric. Twilight moaned deeply into her pillow and clenched it tightly to her muzzle. Her sheets got very wet when she came, the purple mare oozing her release on them as her first-ever climax overtook her.

Twilight kept rubbing and grinding on the now-soaked sheets as she rode out her first, intense orgasm, crying and whimpering out her release into the pillow as she felt the strangely intense yet wonderful sensations rushing through her and making her tremble from them. She felt her newly-discovered muscles clenching hard against themselves as well as feeling her 'privates' and a small thing at the bottom starting to – wink was the best way to describe it? – against the sheets and further stimulate her.

As she finally came down from her orgasm nearly a minute later, with her tensed body finally starting to relax slightly, Twilight started to feel somewhat groggy now as her afterglow started setting in. All of her worries were temporarily washed out the window with the sea of endorphins. She just lay there a moment panting and basking in the soft, peaceful feeling, before she snapped back to reality and realized this was something she didn't understand.

Shaking the newly-developed fog from her mind as best as she could, Twilight felt the lack of knowledge gnawing at her – she needed to know why she felt so compelled to do these strange things, and why it felt so good when she did! Twilight shakily levitated her bookstand from the other side of the room, being unable to concentrate well with her afterglow still present, and brought it over to her bedside table, placing the book upon it then opened the book and turning back to the proper page with her magic.

“Hm...it looks like the rest of this diagram is based past the labia…I guess I'll have to open mine.” Twilight said, her tone oddly deeper then she expected as she looked at herself in the mirror, then watched as her reflection as she slowly moved her hoof down her abdomen, quickly making its way to her wet crotch.

Twilight gasped when her hoof finally met the swollen mound between her legs, soon bringing her hoof down the rest of the way then placing one on either lip. She then carefully spread her puffy lips with both hooves at the same time, feeling herself part for only the second time as she revealed her inner marehood for her own observation. The sensations of spreading herself elicted a pleasured gasp from the inexperienced mare as Twilight's head pressed back hard into her pillow. She moaned deeply, temporarily overtaken by the intense sensations coming from between her legs.

“Oh...my…Celestia!” Twilight moaned, trying to get a reign on the feelings and opening her eyes, not even noticing that she'd closed them tight when she'd first parted her 'labia'. The feelings coming from her crotch were unfamiliar to Twilight, yet so inviting, Twilight's instincts again telling her to do more of –this– with herself. She shook her head to try and clear it again, but it didn't really help as the haze of her need grew thicker. Her body finally had gotten another taste of what it had had before and wanted, needed, more.

Through her developing lust, Twilight looked back at the book and read silently for a short while before saying aloud, “Ok, so past the labia majora is the ‘labia minor’…”. She then looked into the mirror at her spread marehood and after a moment of rubbing and searching, she suddenly exclaimed as she found it. “Oh, there it is!”

Curious what it felt like, Twilight then proceeded to rub over the inner structure with her hoof, causing her to loose another involuntary moan and making her shudder at her touch upon it. She rubbed it again and moaned once more at another unexpected burst of pleasure, her body rewarding her as explored herself deeper for the first time. When she had started to feel very warm all of a sudden, Twilight used her magic to open her window to let some fresh air in, then looked once more at the biology book.

Further inside and past the labia minor is the entrance to the ‘vaginal canal...’

Looking once more at the reflection of her marehood in the mirror, Twilight moved her hooves deeper into herself, biting her lower lip at the sensation it caused her and barely holding back a scream at the feelings such a simple movement elicited. Dear Celestia why does it feel so gooooood?! Twilight wondered – and it was at this time that Twilight had noticed her ‘vagina’ had started to leak the slippery, water-like substance en-masse.

Being ever curious, Twilight collected some of the fluid on her hoof and brought it up to her muzzle. Taking a curious sniff, she discovered that it, in fact, smelled like her, but also had another scent to it she was not unfamiliar with. She knew that scent, finally remembering why it was so familiar.

She'd smelled it many times before. During her Springtime visits with Celestia, both from herself and the princess.

After a little more “experimenting” with her outer vagina and rubbing her needing slit more, Twilight read more from the book.

The vagina, which can expand from three inches to as long as almost six inches unaroused, is a highly flexible, tubular and very muscular passage which is one of the main components of a mare's reproductive tract, its function being to bring in and stimulate the stallion's penis until his ejaculation, pull the stallion's semen to her cervix, as well as to press the foal out of the mare once it's fully gestated. The vagina is mainly composed of bands of muscles and also contains a very high nerve-ending concentration, making it highly sensitive to the touch or other stimulation. In maiden mares, there is also generally a small strip of flesh called the 'hymen', which partially or even mostly covers the entrance to the actual vaginal canal.

Twilight looked at her spread slit and indeed noticed the small band of flesh that composed her hymen, she decided against touching it. Something deep inside her told her it would hurt.

Caudal to the vagina is the 'cervix', which in turn leads to the bi–horned ‘uterus’, or 'womb', in mares. Branching off from the uterus are the two 'horns', which in turn lead to ‘Fallopian tubes’. At the very end of either Fallopian tubes is an ‘ovary’, one of which produces an ‘ovum’, the female reproductive cell, several times per estrus cycle. Uncommonly, two to several mature ova are released in one ovulation, which, if fertilized, will lead to twins, or even triplets developing instead of the far more common single foal.

Twilight used the slippery substance she was leaking to coat her entire vulva, the pleasure caused by the process making her bite her lower lip almost hard enough to draw blood. She then plunged her hoof-tip a little deeper into her 'vagina', pressing harder and earning a sigh at the extremely satisfying feeling of being even further inside herself. As she felt a dull throb of pain, however, she immediately stopped and pulled back.

Twilight continued to read as she pulled out a bit until it stopped hurting and instead moved her hoof a little lower, now eager to discover more of this previously-unexplored part of her body. After that, she felt her curiosity retake her and chose to explore a little lower instead.

…Below the vaginal entrance and at the base of the labia major is the ‘clitoral hood’, which covers and protects the ‘clitoris’. The clitoris is a very highly sensitive bulb-shaped organ and is present to provide additional stimulation to mares during any sexual contact, with the clitoris containing an extremely high nerve concentration in the 'glans', or visible portion, with its 'roots' running along most of the vaginal canal, all the way to the cervix. Mares and other equines can also ‘wink’ their vulva and clitoris, accomplished by contracting the vaginal muscles in a specific way both voluntarily or involuntarily, to attract a stallion to them and spread their natural lubrication, in cases of extreme sexual arousal during estrus or otherwise, and during an 'orgasm', all of which will be discussed later.

Looking once again at her spread passage in the mirror, Twilight quickly discovered her 'clitoral hood' and moved a hooftip to it, then moved the hood up with a gasp to reveal a large heart-shaped pink nub, which was apparently her 'clitoris'. As she looked at it more, she realized that this nub was what had been 'winking' before when she'd felt that intense burst of sensation and since this 'condition' had started, and theorized that it rubbing against the sheets had served to make the sensations even more intense.

Curious as always, Twilight touched the nub with her hooftip – and her haunches immediately bucked into her hoof, that light touch causing a wave of intense pleasure to flow through her and making her start to pant hard as she instinctively continued to rub softly on it, her efforts rewarded with a small gush of fluid from her slit as her clit continued to wink against her hoof, making Twilight experience her first mini-orgasm.

When she came off of it seconds later, the young alicorn was baffled: how could touching herself there feel soooo gooood? "W–Was that an 'orgasm'?" Twilight asked herself, but doubted it. It had felt nowhere near as intense as the previous feeling had, which likely was the 'orgasm' the book spoke of. "Maybe some sort of 'mini-orgasm'? Is that even possible?" she wondered, but decided to get back to learning instead of pondering. Having explored all shown by the diagram on herself that she dared, Twilight decided to move onto the next page, which contained the diagrams of a stallion’s sexual anatomy.

Twilight had seen a stallion’s sheath and scrotum many many times before, as nopony in Ponyville regularly wore clothes, and she had a brother and father, but never had she seen one as up close or in as much detail as the diagrams showed. After she studied the diagram of an erected penis as well as one in the sheathe, Twilight read the accompanying text.

Inside the protective sheath, or ‘prepuce’, is the ‘penis’. The main components of the penis are:

The head, or 'glans', which is at the very top of the shaft. This larger, generally flat–topped portion contains an opening to the 'urethra' of a stallion, through which both urine and 'sperm' travel. There is also the 'urethral process' at the tip of the glans, which typically 'pokes out' during the stallion's 'orgasm', enabling a deeper, more successful 'insemination', possibly enabling cervical penetration and intra-uterine insemination. This portion of the penis is highly sensitive, analogous to a mare's clitoris, and serves multiple functions during 'breeding', and all within this paragraph be explained further in the next chapter.

Beneath the 'glans' is the 'shaft', or body, of the penis. This is the largest portion of the penis and actually constitutes the rest of the organ.

Finally, in the center of the shaft is the 'medial ring', a hard, highly sensitive ring of cartilage which serves to provide additional sexual stimulation during 'breeding', for both the mare and the stallion.

Twilight felt a significant increase in the burning sensation from her haunches at the mention of stallions but ignored her needs for the moment, craving more knowledge as she instead continued to read.

Beneath the penis are two ‘testicles’, or 'testes', contained within the ‘scrotal sack’. The testicles are small-to-mid-sized, roughly egg-shaped organs which produce the male 'gemete', or reproductive cell, known as ‘spermatozoa’, or 'sperm' for short, in very large numbers throughout the entire year. Sperm production generally peaks during the breeding seasons during Spring through Fall during which sexually receptive mares are present, but is always present in some quantity throughout the entire year. There are also a number of accessory glands (listed in chapter 3) within a stallion which work together to produce ‘semen’, a viscous fluid that nourishes and carries the sperm into the female’s reproductive tract in a process called ‘breeding', which will be discussed promptly.

Twilight cocked her head, having never heard or read that term before. “'Breeding'?" Twilight asked herself, "What is 'breeding’ and how do the 'sperm' and 'semen' get into the 'vagina'...and WHY do they get into the 'vagina'?" Twilight asked herself, before turning the page and seeing a large heading of 'Breeding'. "Well, I guess I'm gonna find out!" Twilight said, eagerly rubbing her hooves together in anticipation at the prospect of learning more about this problem she was having, and possibly finding a solution.

Twilight started reading again after adjusting herself, spreading her legs further and moving her tail to the side on reflex as she grew more aroused, her wings unfurled and spread across her bed.

'Breeding', or more officially known as 'insemination' – also commonly know as 'mating', 'sex', 'rutting', 'making love/foals' or many other names or euphemism – often occurs during the ‘estrus’, also known as 'heat’, cycle of a mare, but can occur at any time of year a mare is willing to join in this way with a stallion, albeit without the possibility of 'impregnation', which will be discussed later.

During 'full' estrus is the only time during the year that a mare can bear a foal, as it is the only time of year when a sexually mature mare's body prepares to 'ovulate', or release an 'ovum', also known as an 'egg', which is the female gamete, from the 'ovary follicle' – a mass that forms upon one ovary to house a developing egg each estrus.

Twilight cleared her throat before continuing, her hoof slowly starting to rub her spread marehood as she continued to read.

Exactly when a mare's estrus cycles occur depends entirely on the individual mare, and while they generally occur regularly each month between early-to-mid-Spring and early-to-mid-Autumn for most mares, a mare's heat can actually range to any time within Spring, Summer, or Autumn. Estrus cycles generally sync with those of other close mares' however, such as mothers, sisters, or friends, originally to facilitate group breeding, foaling, and rearing when ponies still ran in herds. During the estrus cycle, a mare will feel a warm-to-hot, itchy sensation of varying intensities deep in their lower bellies, as well as a powerful urge to find and be close to stallions or other ponies during this time, especially ones they hold in close regards or as lovers.

A mare's vulva will also inflame and start to excrete a clear, viscous fluid that serves the duel purpose of both instigating and facilitating mating – containing specific hormones known as pheromones to attract a stallion, as well as also serving to lubricate the breeding process, its composition viscous enough to make breeding easier by reducing friction. The cervix will also dilate and relax and cervical mucus will thin, enabling 'insemination' and 'fertilization' to occur easier.

A mare will also have an increased rate of urination during her heat, her urine also containing pheromones to attract a stallion to her, as uncivilized mares typically urinated where they stood.

Twilight ears perked up as she read that bit, her eyes glittering at the realization. “So that’s what this burning sensation and...leaking...is! It’s my body telling me I’m ready to 'breed'!” Twilight almost started hopping around at that grand reveal, but her enthusiasm was then a bit dampened when she realized she didn't even know what 'breeding' meant yet.

Twilight then turned the page to see a cross–section of a penis inside of a vagina and on the page opposite it a diagram of a stallion's ejaculation into a mare's uterus. Flushed by the explicitness, Twilight increased her hoof's rubbing on her crotch, sighing as she felt her pleasure slightly increase. As she rubbed, she started reading again.

When a feral stallion senses a mare in full heat and comes in contact with her, he will generally approach her and nip at her rear. The mare will then urinate (less commonly observed in civilized ponies) and ‘wink’ her clitoris –which is accomplished by contracting the vaginal muscles in a specific way, with it generally being on reflex, but also possible to be performed voluntarily by the mare– to display her readiness and willingness to breed with that stallion. The stallion’s penis will then erect if it hasn't already, expanding three to four times in size...

Twilight's jaw dropped slightly at that, her instincts kicking in hard as she started to buck against her hoof at the mention of a penis expanding in size. She couldn't help but imagine then the illustration in her book in real life, coming and satisfying her need to 'breed'. She shook her thoughts away as she continued reading, her grinding now making it hard to concentrate on the words as her now–constant movements shifted her so much.

...and getting rigid as the tissues inside engorge with blood. It is this rigidity that will enable the stallion to 'penetrate' the mare’s vagina and initiate the breeding process. While most of the earlier described is more restrained in civilized ponies, the general processes are much the same. The stallion and mare may engage in 'foreplay' at this time instead of getting directly into breeding by stimulating each others genitals with hooves, mouths, or other objects in order to further sensitize and prepare themselves for breeding.

Twilight started drooling and moaned again as she teased her winking clitoris, rubbing that sensitive nub a few times before going back to rubbing her lower lips and reading.

After any desired 'foreplay', the stallion will mount, or climb on top of the mare's back in a specific way...

Twilight looked at another diagram showing a stallion mounting a mare, enthralled by the image and feeling another burst of heat from her snatch.

...and will penetrate the mare’s vulva by thrusting his pelvis in such a way as to cause his penis to spread it and enter deep into her vaginal canal. If the mare was a virgin and not sufficiently lubricated before penetration, some pain and bleeding may be experienced upon the initial penetration as the hymen is ruptured, but this is both very uncommon with a mare in estrus, or even sufficiently aroused, given her extensive lubrication of the tissue, and otherwise is generally very brief and minor.

Prior to, as well as moreso after, initial penetration and during 'intercourse', the mare will create more of their natural lubricant involuntarily to ease the friction between the penis and vagina, with the stallion also generally producing viscous fluids of his own to facilitate the breeding – these fluids commonly called called 'pre-ejaculatory fluid', or 'pre-cum' in stallions and 'vaginal secretions' or 'mare–cum' in mares, with many other euphemisms for both.

The stallion will then proceed to repeatedly thrust his pelvis, engaging in 'sexual intercourse' and causing his penis to move into and out of the mare’s vagina at various paces until enough stimulation is accomplished for the stallion and/or mare to achieve ‘orgasm’, with one orgasm generally setting off the other. There are however many other positions in which the stallion may enter the mare beyond the 'traditional' one – with some positions even allowing the mare to lead the pace of the mating by controlling when and how far the stallion is allowed to penetrate her. More information on different sexual positions can be found in Chapter 9, but any mares wishing to get pregnant will find this position quite sufficient to get the job done.

Twilight increased the force of her rubbing, teasing herself while her vaginal muscles started clenching hard now at the descriptions of sex, her self-stimulation finally starting to kick into high gear. As she read on to the final section of that chapter, she could barely concentrate as the pleasure fogged her mind over.

During an 'orgasm', extreme pleasure is felt by both mare and stallion as endorphins, dopamine, and various other pleasure hormones are released from the brain, and a series of involuntary bodily functions occur. For the stallion, orgasm will result in the penis’ glans ‘flaring’ – or expanding greatly in diameter to prevent semen from leaking out, and to press the 'ejaculate' deeper into the mare’s vagina with further thrusts – as well as the ‘ejaculation’ – or forcing out of 'semen' containing 'spermatozoa' – itself from the penis via the urethra. The ejaculate of a stallion generally contains upwards of four billion sperm, with the sperm being brought up from the epidydimis portion of the testes and joined into the 'seminal fluid' before being ejaculated, with the general ejaculate volume of a stallion being 150cc, or 5 fluid ounces, though can range up to 300cc or more in some rare cases of ponies, or yet more still in the case of zebras. This fluid is generally ejected from the penis with high force into the mare’s vagina by a number of involuntary, rhythmic prostatic and pelvic-muscular contractions, usually reaching or bypassing the cervix."

The urethral process will also harden during and just prior to orgasm, and may forced against or slightly into the mare's relaxed cervix, enabling a well-endowed and fully-hilted stallion to possibly ejaculate directly into the uterus itself, almost guaranteeing a fertilization and conception. This kind of cervical penetration is perfectly normal and common among equines, and is indeed the best way to maximize the odds of a mare's pregnancy, though may be considered uncomfortable by some mares.

Twilight paused reading to clench her eyes shut and release a moan, the sensations coming from her dripping–wet 'vagina' causing her head to press back hard in the pillow, making her grit her teeth for a moment as a particularly strong burst of pleasure rushed through her when she teased her clitoris more.

Barely able to read now, Twilight almost gave up as her vision started regularly blurring from the sensory overload her self–pleasure was causing, almost making it impossible to read the fairly–small print. Needing to know what happened next though, she forced herself to read through her blurred vision and nerve–wracking pleasure.

For the mare, orgasm will cause the muscles in the abdomen, vagina, rectum, and uterus to involuntarily contract and relax rhythmically – further stimulating and encouraging the stallion to ejaculate more as well as thrust more repeatedly and deeply into the mare, to introduce the semen further into the mare's reproductive tract and potentially induce a cevical penetration. The involuntary contractions from the mare's vaginal and uterine muscles also draw the ejaculate and sperm deeper into the vagina and uterus, making later 'fertilization', or joining of the ovum with the sperm within the Fallopian tubes, more likely. The ovum will then likely be fertilized upon release from the ovary after the breeding between a mare and stallion, the two gametes combining their genetic information to form a single-cell 'zygote' that multiplies quickly. This joining of sperm and ovum , known as conception or fertilization, is the start of a mare's 'pregnancy' which will be discussed in the next chapter...

After "studying" the diagrams further, especially the ones of the penis, and of penetration and ejaculation, Twilight started to rub her now soaked and burning sex roughly now, her need beyond any need she'd ever before felt. Setting the book down, she now focused more on the sensations she was getting from her nether region then the text, pressing between her lips and into her hole as far as she could without it hurting – then cried out in pleasure as her wanting passage winked against her hoof in response.

Twilight watched herself in the mirror the whole time, watching her hoof rubbing her genitals and turning herself on even more as she saw what she was doing with herself. With every rub she would increase the force and speed of her efforts, starting to pant hard as pleasure coursed through her.

When she imagined her hoof was instead a stallion's penis however, Twilight's pleasure increased exponentially. She pulled out her hoof, then imagined a stallion mounting her and rubbing his 'penis' against her 'vagina', imitating the 'glans' rubbing against her lips with the tip of her hoof. As she imagined him thrusting into her to the hilt, she pressed her own hoof as deep as she dared, shivering in pleasure from the extra stimulation her imagination provided her with.

After a few more moments of rubbing rather roughly into and around her passage, imagining the stallion now thrusting into her and matching each thrust the stallion in her mind gave her in real life with her hoof, she felt everything coming to a head again as her clit was starting to wink against her hoof now.

Twilight suddenly gasped and cried out as she arced her hips up into her hoof, another intense orgasm overtaking her body again as wave after wave of pleasure wracked her. The powerful sensations made her slam her head back into her pillow repeatedly as her body continued milking and grinding against her hoof, each rhythmic contraction sending a wave of tingling pleasure throughout her.

All while she was cumming, Twilight was barely able to breathe from the intensity of the orgasm, with each contraction of her passage causing her vision to grey out occasionally as she gasped for air through the intense release. Her fluids gushed and even squirted out onto her sheets once more, soaking it further in her mare-cum as she continued to rub hard on her slit, subconsciously riding her orgasm out as long as she could.

Twilight continued a chain of orgasms for another full minute, the extensive teasing from before and her fantasy with the stallion overstimulating her as she kept grinding her hoof over and into her soaking passage, continuing to shudder and tremble and moan out through her much–needed releases. Occasionally, she'd nudge her clit with her hoof and add that extra edge to her already blinding pleasure, making her moan or occasionally cry out again at the added surge.

Twilight's body finally calmed down moments later, her tensed muscles relaxing and giving her a chance to breathe properly as her intense orgasms finally ended and the soothing afterglow began. In her post–orgasm bliss, Twilight barely managed to keep a hold on consciousness as her eyes hooded and nearly closed, a small smile crossing her face at feeling so relieved and so good that she just wanted to cuddle up with her pillow and drift off to sleep. “Wow...t–that was amazing! Why have I never tried this before?!” she asked, though there was nopony to answer that but herself.

After resting for a number of minutes, feeling like a bunch of twitching, wonderful–feeling mush laying on the bed; Twilight finally accomplished getting up, getting a drink of water from downstairs and cleaning up her rather large mess from her "learning session", including throwing her soaked bedclothes into the washer. All the while, she still felt somewhat spaced–out from her rather intense orgasms minutes ago...but it had been sooo worth it.

As Twilight felt the burning in her rear start up again a few minutes later, although now less intense thanks to her taking the edge off earlier, she sighed in disappointment. Why didn't that "orgasm" just end her heat completely?! Curious now as to why her estrus had 'started' again, Twilight picked up and opened the book with her magic to see if there was a way to actually stop her ‘estrus cycle’ and therefore the burning – starting to read a section she'd previously skipped as she'd started rubbing herself, not thinking it relevant at the time.

A mare’s 'full' estrus cycle will generally end naturally after a period of about five to seven days without breeding, or after a successful breeding session resultant in a stallion ejaculating inside the mare and impregnating her. If the mare was bred but not impregnated, the mare will go into heat again soon after – generally within a few days, but in some instances even within the same day."

"As a technical note, there are also other ways to stave off a mare's heat and the sensations alongside, with this generally through 'masturbation', or stimulating one's self, or with 'sex toys', which are generally artificial peni. These methods, however, only provide temporary relief and must therefore be administered regularly to keep the mare's hormones and breeding urges under check. There are also ways to completely end a mare’s heat for a short time – including potions and–

Twilight turned the page again and was slightly surprised when a sealed note dropped from inside the book and quickly landed on the wood floor, the wax seal upon it weighing it down quickly. Levitating the note up off the floor with her magic, Twilight broke the seal and read the note upon seeing her name written upon it.

My dearest student Twilight,

If you’re reading this, it means I believe you have grown and learned enough about friendship and companionship and have entrusted you with learning about sex and reproduction, which may lead on to something even deeper then even friendship: love. As sex ed is mandatory in classrooms, and everypony else in the castle knows what sex is, I can safely presume you'd be the only one borrowing this book from the Royal Archives.

Due to your curiosity and knowing your habits, you’re likely reading this note during your estrus. As I strongly I expect you are, I have a task for you and expect you to immediately partake upon it upon finishing this letter: you are to travel to Zecora’s hut and ask her to prepare seven 'Heat Potions’ for you. This potion will end your estrus cycle and fertility for the day, and thereby any discomfort you may be feeling...

...unless of course you have a special somepony you want to share this time with instead! ♥

Forever your mentor,
☼ Princess Celestia

Twilight giggled and shook her head at the last sentence, figuring it was just Celestia pulling another prank on her as she was wont to do. Twilight figured that Celestia knew she wouldn't be romantically interested in anypony upon reading that book and was instead just teasing her as she so often did.

Still, Twilight wasn't one to reject the Sun Princess’s missions, even if it meant possibly putting herself in danger in the Everfree Forest. Twilight immediately packed her saddlebags with a few items – a few carrots and bottles of water just in case she got lost, the book on reproduction, and another book involving basic unicorn spells so she could ask Zecora if any would help with her current or future heats– and Celestia's note. She then headed off to the Everfree Forest, off to complete the task her mentor had set her upon.