It had been a number of weeks since Spike and Twilight had first revealed their true feelings to each other, spending time with each other as they usually did but now with an extra edge to their normal behavior with each other. They would occasionally nuzzle or softly kiss when passing each other in the library whether during work or off-time, sometimes with it escalating to what they'd done on that first night, which Twilight did extensive research on it and learned was called 'making out'. She'd learned of it before in her earlier studies on pony behavior, but had mostly forgotten about it given her previously non-romantic lifestyle. Then she proceeded to learn as many ways of 'making out' as possible, studying this lovely new thing to her heart's content.

During this time it was early Spring, and like most mares during Spring, Twilight had started feeling more...frisky as of late. She started to get more aggressive with her affections with Spike, taking on the lead role more and more during their make-out sessions as she felt that need starting to grow within her.

Spike started to notice a lightly-musky scent around the library now, also noticing that Twilight had not left the house for the past day except when her Princess duties called for it, always acting highly agitated and constantly keeping close to him. Very close. Spike was no dummy to what was going on with her however, with Twilight having taught him about mares, stallions and this time of year when he himself had grown of age to breed – teaching him and having him study on the subjects of equine, and what little was known of the far-less-researched draconian, reproduction.

Spike knew Twilight was in estrus now, accepting that she would just be more moody and a lot more clingy for the next few days until her full estrus passed, then would be the same way again in a couple weeks when a second wave of it came, and so on until the end of that breeding season. He was used to it by now, having lived with her for so many years and knowing that even with that estrus-suppressing spell she usually used, Twilight still experienced some of the lesser mental symptoms of her heat if not the physical ones. Even after much study and tweaking by the unicorns, the spell was still unable to eliminate the deeply-rooted urge of the mares to be close with stallions, or at least with those close to them, throughout their heats. Twilight as such had always wanted to cuddle with Spike during her heat every year before, but their true feelings for each other coming out really seemed to ramp that up this year.

~

"Spike can you come up to my room please? I need your help with something." Twilight asked Spike, getting a nod from him as he placed the last book from that stack onto the shelf, then climbing down from the ladder. As she indicated for him to follow her, Spike saw Twilight's tail swishing rapidly as though she were agitated – and knew she probably was, given she told him she hadn't used the estrus spell this year. When he'd years past asked why she didn't use the spell some cycles, Twilight had explained to him that the spell was only to be used when absolutely needed or else it could possibly cause, in the cases of extensive over-use, permanent infertility or possibly other reproductive-health problems in the ponies it was cast on. That, while the being cast on a pony a few times every year was totally safe, additional castings over four per year were somewhat more risky, and with the spell only lasting a day or so of the usually three to seven day cycle anyhow, it rendered it useless but for during very important times.

Spike watched as Twilight suddenly dived onto her bed as he'd entered the room, her tail flagging instantly and her whole pussy and rear put on full display to the adolescent drake behind her. She'd been wanting to do this ever since Spike had told her of his true feelings for her, then had asked her to be his mare the next day after she awoke. She was only too happy to accept, but never before found a proper time to fully sanctify his claim and truly become his until today, her schedules always so hectic or the mood and timing never seeming just right to her.

Twilight knew that she'd just come into her standing estrus a couple of hours ago but already it was ravishing her body, her instincts overwhelming her with the desire and need to breed, to accept a stallion into herself. The need for a stallion to breed her, and fill her belly with his foal. She decided that now was finally the time to show her true love for Spike, and for her to become his mare in more ways then one.

"C'mon Spike, I closed the library early today so we can be all alone. I think it's time you and I learn something books can't teach us, huh?" Twilight asked as seductively as she could, swishing her tail to put emphasis on what she intended, permeating the room more with her scent; the scent of her pheromones that would have driven a stallion wild with lust, but went largely unnoticed by Spike given he was of a different species.

All Spike had ever noticed prior when Twilight went into season was that she smelled a little more musky for a few days, and was much more cuddly with him, but it never really did anything to him beyond that...but what did do something to Spike was just how she was acting towards him now, his cheeks growing flush as she'd so suddenly and blatantly presented herself to him after asking him to simply come upstairs with her.

Spike slowly approached her laying form but was unsure about this situation he was suddenly thrust into, never before having seen Twilight like this. She had always used that estrus-stopping spell on her most intense first cycle all previous years, but knew that this one she hadn't. Not needing it now that that she had a male who could help her...well, maybe.

"T-Twilight, are you sure about this? You're in heat and...might not be thinking clearly." Spike started, only to look down at Twilight. She was sweating, her rear saturated with her fluids and clearly showing how much she needed attention, her marehood very inflamed – and the way she whined and winked her clit at him, it virtually made his heart break. She looked horrible, needing a stallion to sate her heat...but Spike could only wonder if he even could be that "stallion", if he could even help her at all given they were a different species.

"Spike, please, this estrus is so bad...I feel so hot. I love you, I need you. I need you to breed me and stop this burning." Twilight begged, her voice just above a quivering whisper as she spoke, her loins almost feeling like somepony was holding her lower belly over an open fire. She squirmed as she awaited her partner, her clit winking non-stop to Spike on reflex to a male she loved being behind her, "Please..."

Spike stiffly nodded to her after only a couple seconds as the sudden shock of this happening so quickly wore off, his agreement making Twilight give a very relieved sigh. "T-thank you Spike. I knew I could count on my number-one assistant to help me in my time of need." she said with a chuckle, remembering how much that nickname had meant to Spike when he was still considered a baby. How much it still meant to him, even if he brushed it off as if it were nothing but an old kiddie name.

"So...uh...w-what do you want me to do exactly?" Spike asked as he knelt down behind Twilight and sat down, his snout level to her quite-presented crotch. He gave a gentle sniff, confirming the same musky scent he'd always smelled before but so much stronger now that his nose was almost touching her slit, finding the winking of her clitoris to be oddly arousing now that she was winking to him, showing her need for him in the most primal of ways a pony could.

"Well, you remember that book on p-pony reproduction? You know, the one I made you read when you were curious about why I acted this way, I think...that one time I didn't use the anti-estrus spell during that week-long studying spell? I think it was just as you were coming into adolescence...?" Twilight asked as she struggled to remember the title, the sour look on Spike's face clearly showing he did.

"'Breeding Education for Young Stallions and Mares'? Ugh, do I..." Spike confirmed, remembering all the gross details about foaling and what happened immediately after it as though he'd just read it, with most Purple Dragons having a photographic memory...even if they did sometimes forget small things.

"R-remember the section on com-common foreplay practices among ponies?" Twilight asked, the only-warm breaths Spike was loosing on her sensitive sex feeling almost scalding in intensity, with him unintentionally teasing her arousal even higher. When he nodded, Twilight continued, "R-remember the section in which the stallion uses his muzzle and tongue to stimulate the mare's vulva and vagina?" Another nod. "S-Spike, I need you to do that for me." Twilight begged, then rolling on her back and spreading her legs slightly more, using her hooves to make her vulva slightly part now and expose the deep pink inside of her vagina to him in a most obvious invitation. "P-please?"

Spike only looked on in awe as Twilight exposed her most private sanctum to him, never having seen her like this before - never having seen her so desperate for a male, for him. "You mean where the stallion put his tongue...in...in there?" Spike asked, sticking his tongue out experimentally and looking at it. Like most dragons, Spike had a very long tongue in proportion to his body size, with it easily reaching his mid-abdomen when fully extended – and he stood about 4 feet tall, about half-a-head taller then most mares.

As Twilight looked back and saw Spike's long, skinny, and from her experience very prehensile, tongue sticking out, she felt another burst of heat from between her legs as she remembered what it had felt like in her mouth...and could only imagine what it would feel like between her legs. She needed that tongue again, but now she needed it inside her marehood. Right. Bucking. Now.

"Spike, yes, please. Oh by Celestia, please p-put it in me." Twilight begged, only then noticing how submissive her tone was. She later chalked that up to the extensive amount of reading she'd done on dragons through her schooling, though mainly focusing on it after Spike had hatched through present day. Those readings were meager given how little contact ponies had had with dragons throughout the years, but she had gathered from them that male dragons loved to be the dominant ones when it came to any relations, whether with other species or within their own, especially during migrations or breeding seasons.

Dragons were only observed actually mating once by one pony, but the author claimed in the book that he'd had a bad front angle and couldn't actually see the act taking place, adding that he couldn't move to see more lest he be spotted and, at minimum, interrupt the breeding. He however had written that he'd definitely seen enough to know that dragons were ferocious, feral breeders, with the drake giving the dragoness no mercy and mating her repeatedly after he'd mounted her, and did not climb off her back until he was done. He'd said they bred once right after the other until either the drake's semen reserves had run dry, or the drake was certain he'd impregnated the dragoness.

After the drake stopped his thrusts and hilted, the author wrote that the dragoness had cried out alongside him, her hips grinding against the male's – and the cry didn't seem to be in pain judging by the female's very pleased, seemingly orgasmic expression and sounds. The author had also noted that the male remained inside the female for a number of minutes after each orgasm, seemingly either unable to free himself from her for some reason, or simply unwilling to and wanting to remain as deep inside as possible, to keep his seed fully within her to increase the chance of conception.

The more she though about it now as she lay presenting on her bed, with her dragon's scalding breath washing over her slit and underneath to her teats, the more Twilight realized how much she looked forward to all of it. How much she looked forward to her dragon rutting her.

"Spiiiike!" Twilight whined out when her hopeful mate hadn't reacted as quickly as she'd hoped to her very open invitation, squirming once more as another burst of heat surged through her body. As she felt him still only breathing on her some seconds later, she looked back and saw him staring at her spread lips and winking clit while stone still, seeming unable to even do much more then breathe. Great, she'd scared him. Deciding she'd instead have to take the initiative, Twilight lit up her horn and gave Spike's head a gentle push forward – and gave a sharp, involuntary yelp as she finally felt his scaly snout rub against her swollen and extremely over-sensitive marehood.

Spike had quickly pulled back in surprise to suddenly being pressed against her wet crotch like that and upon hearing her loud exclamation, but as he licked his lips and tasted the lightly-salty but more sweet flavor of what she'd left there, he quickly found himself wanting more. Much more. "S-Spike want." he softly said, his dragon greed kicking in again. He wanted his mate now, and he was going to take her.

Twilight sharply gasped as she suddenly felt Spike's thin tongue working over her outer lips, apparently cleaning up the extensive amount of her fluids already there as his claws took her hooves' positions of holding her open wide, with Twilight conceding the right as she shifted and drew her hooves up to fold under her chest. "Y-yes Spike, I'm all yours! Take me mooooore! I'm all yooooours!" Twilight moaned deeply as she felt him suddenly push his forked tongue into her a few moments later, apparently having cleaned her lips of her nectar and now seeking more from its source.

The thin but very flexible muscle swiftly worked deeper into Twilight's spread marehood, leaving her momentarily stunned at just how good Spike's tongue felt, almost tickling along her canal with its forked tip. When a stallion's tongue could have gone no further, Spike's tongue only kept snaking ever deeper into her marehood, his ministrations forcing whimpers of pleasure from Twilight as she panted now, so overtaken by just his tongue that she couldn't imagine how the rest of him would be. Bringing her to wonder just how all that would work anyways.

Even after all the years they'd been together, Twilight had never before seen Spike's...penis. He'd never needed a diaper like pony foals did, with most dragons instinctively seeking to 'do their business' away from their sleeping areas or homes, and Twilight using that instinct and a baby dragon's highly-developed intelligence to quickly and easily teach Spike to learn to use a toilet...after only a few misses.

Even when he'd reached adolescence and undoubtedly had the urges to mate that came with it, he'd never been caught by Twilight satisfying himself, always very discreet about when he did 'it' and apparently waiting for her to leave the house or to do 'it' away from home.

Now that they were being intimate, the curiosity of what Spike looked like 'down there' was virtually killing Twilight as he licked her – but even through her curiosity, she couldn't ask Spike to leave her now that she'd felt his tongue within her. It just felt too good to even think of him stopping!

It was only a matter of seconds after he'd entered her before Spike felt his tongue-tip rubbing on something deep inside Twilight, finding what felt like a small, looser ring against a wall. "Twi-ight, waf thif?" he asked, unable to speak properly given his tongue was currently buried within his mare. As he tried to speak again and ask if she was alright, he felt Twilight shudder at the vibrations his voice and movements his tongue made within her as he spoke, making Spike feel another clench on his tongue and hearing another deeply satisfied moan from her.

"S-Spike, that's my...oh Celestia, that's my c-cervix!" Twilight barely managed to stutter out, feeling just how deep he was and in total ecstasy at having something that far within her, with that depth being unheard of for a stallion's tongue. "Oooooh Celestia, you're so deeeeep!" she moaned out as she felt the light, almost tickling yet satisfyingly firm sensations of his tongue all along her passage and against her cervix as his tongue wriggled around in her, thin but strong - and he was just showing her how flexible as well. Twilight felt as his tongue wormed around in her, feeling its tip moving along her inner walls as it bent and twisted and doubled around itself within her, with Spike apparently exploring her whole passage with his tongue.

It wasn't long until Twilight felt him hit a particularly sensitive spot a couple of inches from her entrance in his slow exploration, making her give a small cry and wrap her hooves tightly around the back of his head. Her back arched up as she pressing her hips against his snout on reflex, burying him deeper into herself as she felt a sharp burst of pleasure. "Oh S-Spike please...l-lick there again?" Twilight begged as she held him tightly against her crotch and didn't really give him a real choice in the matter, wanting, no needing, to feel that again. Twilight knew Spike must have hit that mythical spot that all the biology books she'd read had only hinted at, the massive burst of sensation making that the only explanation. He'd apparently found her G-spot. Hard to miss, given he had every inch of her marehood covered at once after all!

As Spike did as asked and licked her 'there' again, Twilight felt herself tensing, knowing she just needed a bit more... "O-one more time. Sp-Spike, please!" she begged breathlessly – and as she did feel him lick against that spot one more time, that was it.

Twilight cried out in a near-scream as she had the most explosive orgasm she'd ever experienced, her inner walls squeezing Spike's tongue for all it was worth, her clit winking rapidly with each contraction and massive bursts of pure, orgasmic pleasure surging through her, her juices spraying onto Spike, then oozing out and onto the floor beside her bed.

Twilight was held in that state of ecstasy for nearly a minute as Spike kept diligently licking on that spot, with him not remembering why licking right there had triggered Twilight's orgasm, but now wanting to make her feel good for as long as possible now that he had. He was no foal when it came to sex despite never having been with a pony before in such a way as this, with him not only having studied and memorized the book on pony sexual behaviors and anatomy, but also personally knowing how good it felt to have an orgasm. After all, he was an adolescent drake that was no stranger to his own claws. Now that he had somepony to share that knowledge with, nothing gave him more satisfaction then to bring that kind of pleasure to his mare.

Spike didn't stop licking until Twilight had released her bear-hug from his head and instead gently started to push him back as she grew too sensitive down below, to which he quickly removed his tongue from her before then licking his lips, savoring the last of her juices he'd gotten. "Mmm Twilight. You taste better then a sapphire cupcake!" Spike exclaimed, but quickly noticed that Twilight now looked even more desperate than before he'd licked inside her! Twilight whined in her need now as her inner stifles and flank were saturated in her juices now, her clit winking even more frequently than before. "T-Twilight, what's the matter?!" Spike asked, clearly worried at seeing her condition degrade because of him. "What did I do to you?!"

"I-it's OK Spike, this is t-totally...n-normal. For a m-mare in full estrus, foreplay only makes them n-need the stallion more, to become even more receptive to him. S-Spike, I NEED you to breed me. NOW! Twilight exclaimed, once again rolling onto her stomach and flagging her tail to him, putting her winking, soaked marehood on display to him once more.

Spike knew the basics, but wasn't practiced at all, his claw no real preparation for the heated, begging mare before him. He felt himself fully erect now from the very arousing show Twilight was putting on and from having brought her to orgasm, but wasn't sure how to proceed. "Um...Twi, do I just...do you just want me to...to, well...stick it in?" Spike asked with a confused tone, seeing Twilight's back legs trembling lightly as she impatiently awaited her 'stallion'.

"Y-yes Spike! P-please!" Twilight begged, raising her rump higher in the invitation; "t-treat me rough, just like a dragoness!"

"Ok, here goes," Spike said with some hesitation, then gripping himself with a claw and lining himself up with Twilight's dripping wet slit.

Author's Note

Mares in heat, gotta watch out for them.