This chapter contains extensive anatomical exposition, studying, and recording of scientific descriptions of the structure and functioning of a dragon's penis (in my mind). If you want only strictly sexual content, go to the next chapter.

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Twilight just then realized something as she felt Spike's narrow tip rubbing between her lower lips, realizing that this was likely the first actual recorded instance of a pony and a dragon mating that she knew of! As she discovered this, she realized that she was making history, that this needed to be documented. She needed to remember and record everything so she could to make future notations of it, and possibly remember it much later on. For science, of course.

As much as it pained her, Twilight spoke up. "S-Spike, I need you to stop." Twilight said, instantly feeling what little of Spike's tip he'd put into her slide back out instantly, earning her another burst from her heat at his absence. Spike simply sat as she left the room for a second, puzzled as to why they'd stopped so suddenly just as they were getting to the good part. Twilight came back in the room moments later, returning with a camcorder levitated in her magic, the sight of which made Spike immediately tense up.

As Twilight started setting up the tripod the camera sat upon at the end of the bed, Spike moved beside her and watched as she instead removed the camera, turned it towards herself and started speaking: "This is Princess Twilight Sparkle of Equestria starting a case study of the possibilities of equine-draconian interbreeding and whether or not it is even possible at all. With me is a willing adolescent drake named Spike, who will be breeding with me toda—HEY!" Twilight finished with a yelp as Spike snatched the camera from her magic and turned it off; "Spike, this is going to be valuable research material that ponies need to know! We're making history! Recording it is important!" Twilight said, the wood floor giving a solid thwank as she stamped a hoof on it.

Spike sighed, turning the camera over in his claws as Twilight merely watched, not wanting to offend him by simply taking it away without regards to why he'd interrupted her, but at the same time feeling her need to document gnawing at her. "I dunno about recording our first time Twilight, even if it is for science. I mean, isn't this kinda thing supposed to only be between a mare and a stallion...though I guess in this case a mare and a...a drake? Doesn't recording it just, I don't know, make it seem... I don't know, wrong to you?" Spike asked, slowly turning the camcorder in his claws, awaiting a response.

"Spike, this would be the first recorded instance of a pony and a dragon mating...EVER!" Twilight insisted, knowing that something like this needed to be carefully documented and studied, to be recorded for the advancement of knowledge itself! "Spike, this is very, VERY important for science! We need to know what happens during and possibly after the mating, and possibly if the old legends of kirins and other pony/dragon hybrids are true!"

Spike looked down to the device in his claws, knowing that Twilight was right. This was about more than just dignity or love now; this was about helping ponies learn more and to become closer to understanding nature and themselves. Spike nodded as he held the camcorder out to Twilight, who then picked it up in her magic again and turned it on. "Science thanks you Spike." Twilight said, once again going back to her documenting voice; "The drake has agreed to allow this study to continue, so we shall. I should note that I am in full estrus at the moment, so I apologize in advance for any lack of...professionalism during this study. Now without further ado, I shall proceed to study the dragon's anatomy."

Twilight then moved herself so she was sitting facing Spike, and for the first time she saw Spike's dragonhood - then gasped as she saw a second! "Well, dragons apparently have two penes as compared to a pony stallion's single penis, though they appear comparatively slim overall as compared to a stallion's. The penes also appear to come out of a genital slit instead of a sheath, similar to other reptiles. The genital slit has the general look of a mare's vagina, except that it is horizontal and coming from between two of his scale plates instead of being made of skin. There is also a concave inner portion which resembles an actual vaginal entrance only much larger; an elongated, eye-shaped slit from which they emerge, with the penes themselves aligned horizontally, side-to-side that is, to each other." Twilight said as she moved the camera over Spike's crotch and genitals, recording every detail.

"Each of the penes appears to be approximately the average length of a young stallion – about twenty centimeters, nearly eight inches, long, with the penes seeming to taper larger instead of a stallion's large, constant length, a drake's starting out fairly thin only to grow thicker until it grows very thick at the bottom. In terms of diameter, they appear to go from from one-point-five centimeters, or about half-an-inch, in diameter at the tip to about five centimeters, or nearly two inches, at the base, with both smoothly tapering up in size." Twilight said in the cold, clinical voice she always used when studying or analyzing something, making Spike realize just how much this was killing the mood.

"Are you almost done with this Twi, I'd...kinda like to, ya know, get on with it..." Spike said as he shifted in eagerness, his penes giving a visible throb.

Twilight understood the sentiments as she felt another surge of heat from between her legs, having utterly forgotten she was in heat for a moment as her quest for knowledge took over. "Just a little longer, I promise..." Twilight said, getting only a puff of smoke from Spike's nostrils, with him making it quite clear he wasn't enjoying being treated as a test subject instead of a lover.

Twi gave Spike a kiss on the top of his muzzle before returning to his lower body, deciding to work quickly so they could 'get on with it' as he'd said. "I believe I can see some additional, rounded swelling about an inch from his bases contributing to the size of them, with the remaining length behind there rather small in diameter. I am not sure what that swelling is, but am nonetheless making note of it." Twilight said, then soon after realizing it looked similar in structure to a canine's 'bulbus glandis', or 'knot'. Noting the possible similarities aloud, she moved on.

"Along the penises' lengths, a large number of very small triangular-shaped slits can be seen, growing longer as they reach the bottom and stopping just before the swollen portion..." Twilight said, then lifting one slit with her magic and slowly reaching inside and pulling out its contents, eliciting a soft gasp from Spike and seeing his hips shift upwards as she did. "The drake apparently finds stimulation of this part of the penis very pleasurable." Twilight notated, and upon lifting the rest of them with her magic and extricating all that was inside them, she quickly found that they were in fact coverings for a line of thin, clear, spine-like nubs with the points facing backwards. She could see pink flesh inside the harder casing, notating that the apparent 'breeding spines' were not unlike an animal's claw in composition.

Twilight decided to see if Spike could tell her more then she could merely see. After all, they were part of him. "Spike, do you know what these spines and swelling are used for in dragon mating, or have any clues at all? Surely you've...masturbated before?" Twilight asked, nudging the swelling at the base of his penis, as well as one of the many clear spines going straight up the top and along either side of his penis with her hoof-tip, noting the spines started getting longer and larger near the knot and apparently grew shorter as they neared the tip.

Hearing Spike moan softly and hump his hips as she again rubbed a hoof-tip over one, Twilight realized that the spines must be very sensitive to being touched and moved. As she had touched it, she also felt that they were firm but flexible to the touch, finding that they must be made of some sort of hard cartilage or something similar. She also realized the spines weren't at all as sharp to the touch as they looked as she touched the tip of one, instead finding it to be firm yet pliant as she pushed down gently on it and felt it bend under her hoof not unlike a very stiff hair would, getting another muffled moan from Spike.

Spike's blush grew hot as his usually subtle self-pleasing was brought to light, but realized that was trivial compared to what they were about to do. "Well, the spike-thingies come out as I get past my big swollen parts the first time, then more and more as I get closer to orgasm, making it hard for me to really rub anymore given how sensitive they get..." he said, then pointing to the now-slightly-more-swollen roundness at the bottom - "...then the things at the bottom get bigger and the part behind them get really, really sensitive when I'm just about to blow. Then when I rub behind it, it feels really good, the spines go out all the way and the bulges at the bottom get huge...and then I...cum." Spike concluded, blushing furiously now, with Twilight both physically and mentally recording everything he'd said.

"Wait, drakes DO have knots? Spike, show me." Twilight demanded as she heard of the bases swelling heavily near ejaculation, only to see Spike's eyes grow wide.

"Ex-excuse me?" Spike asked, not sure he'd heard her right. Surely she couldn't mean...

"Spike, I would like you to masturbate in front of this camera and show me and all of Equestria how dragon penises work." Twilight again requested, quickly adding with a blush; "F-for science, of course."

Author's Note

Dragons sure have interesting sex organs, huh?