Twilight's trip back to the library was, for the most part, more mundane than she had been hoping for. The sun was getting low, and most of Ponyville's residents had retired into their homes for the evening. Shops were closing, lights were dimming, and the few ponies still out and about hardly caught Twilight's attention.

Wait... Twilight looked around at the scant pedestrians, most of them still mares, yet she had to actively direct her attention to their breasts and asses when earlier that morning it was impossible not to look at them lustfully. Even better, her dick stayed mostly flaccid despite where she directed her attention. Maybe a few good lays were all she needed to clear her head, and tomorrow she could go back to a normal routine. That would be good, right?

The thought was both relieving and almost disappointing, but before Twilight could reflect anymore on that last part, she was interrupted by a shout from overhead. "LOOK OUT!!!" a voice cried from above. Twilight turned to face the oncoming sound when it came crashing directly into the alicorn, sending her tumbling across the ground and landing with something on top of her.

Or, as it turned out, someone.

Derpy lifted her head from the soft pillow she had landed on, cursing herself and her wings for getting thrown off by a strong wind. Again. She glanced below her, her hands gently squeezing her landing cushion, and realized her softer crash was the result of the lavender thighs resting on the ground beneath her. She turned her head to look behind her, and nearly panicked when she saw that she had crashed into the princess. "Oh, I'm so, so , SO sorry about that. Are you alright?"

Twilight stirred and opened her eyes, her hazy vision clearing and locking directly with the space between the delivery mare's legs. Her shorts were rather tight against her hips, giving her a distinct outline on her vagina and especially her ass. It didn't compare to someone like Pinkie, but it's size on Derpy's smaller frame still gave it the appearance of being quite large. The sweet sight before her caused Twilight dick to rapidly harden, lifting past her skirt and exposing itself to Derpy.

Guess it was never going to be that easy...

Derpy turned to look back at what had entered her peripheral vision, coming face to face with Twilight's throbbing member. "Oh my" she muttered under her breath, gently lifting her hand to brush her fingertips against the large shaft. It was bigger than any she had seen before, yet even more sensitive as her lightest touch made Twilight's cock twitch with excitement. Not only was this one bigger, but Derpy was pretty confident that this was the best dick she had ever seen. The smell was alluring, drawing Derpy to move her muzzle closer and take it in, making her head spin with arousal.

Twilight was a little surprised that Derpy hadn't yet gotten back to her feet, but that was before she felt the mailmare's soft fingertips and steady breaths against her shaft. She could also see the small damp spot forming between Derpy's legs, and before she knew what was happening, she reached up to pull the mare's shorts and panties down in one swift motion. The sight of her moist, puffy lips and the small strand of precum still stuck to her panties sent Twilight straight back into her heavy lust, taking only a moment to admire the pussy in front of her before burying her muzzle into it.

Feeling her lower half exposed to the cool air only to then be smothered by the princess's mouth elicited several moans from Derpy, her front half collapsing forward and her muzzle buried into the base of Twilight's stallionhood. Twilight lapped at Derpy's pussy, pulling the lips apart coaxing more and more of the mare's juices from her snatch, while Derpy slowly stroked one side of the alicorn's cock and began dragging her tongue up the other side.

Despite them being directly in the open for any passing pony to witness, both Twilight and Derpy were lost to their arousal, each of their actions growing more and more intense. Twilight dug her hands into the soft cheeks above her, and Derpy rose to the tip of Twilight's dick and wrapped her lips around it, sucking as much of the princess's precum as she could. Her hand continued to stroke the shaft, urging more of Twilight's fluids to escape into her waiting mouth. She slowly began to pump her mouth up and down the shaft, slowly sinking further and taking more of Twilight into her mouth.

Derpy could tell that Twilight hadn't ever given oral to a mare before, but she didn't really care; Twilight's eagerness to explore every inch of her love tunnel more than made up for a lack of technique. Twilight shifted one of her hands to come underneath the mailmare and rub her clit, driving Derpy closer to her climax. It wasn't much longer before she felt her orgasm come over her, spilling a large portion of her fluids over Twilight's lips and face. The cock in her mouth twitched violently, and Derpy felt the rush of sperm flood into her mouth, quickly filling it and forcing her to rapidly swallow the oncoming waves of semen.

When Derpy managed to consume it all, she left Twilight's cock with a very audible pop as she gaped to replace the breath she had lost. She was so lightheaded that she hardly noticed her partner slip out from underneath her and station herself behind her. "I hope you're ready, Derpy," Twilight said as her dick rested against one of Derpy's ass cheeks. "cause I'm going to plow this pussy so hard." Twilight cupped her hand over the mailmare's quivering lips and pushed her palm against it, earning herself a drawn out moan from the delivery pony.

Twilight smacked her cock against the mailmare's ass, squeezing the two cheeks around her rod as she occasionally thrust between them. "I can't wait to be inside you, Derpy. I bet Amethyst and Dinky will be so excited to find out they'll be getting a little sister," she teased as she slipped between Derpy's legs to rub her head against her labia.

"Wait, *mmph*, you're- you're gonna..?" Derpy could barely finish her sentence as the tip of the shaft beneath her brushed past her clit over and over. She felt the cock pull back and line itself up with her parted lips. Twilight began to push in, bringing Derpy back to her senses for the briefest of moments. She had been in this kind of situation before, and remembering just how those night turned out in the end prompted her to get at least one request out before she was rutted. "Wait, Twilight, before you... just please- please don't leave me... like they did."

The soft plea snapped Twilight out of her ravenous lust. She looked down at the mailmare and saw her huddled up to herself, just expecting Twilight to ignore her request and fuck her anyway. Even though this was perhaps the most mutual sex she had up to this point, she couldn't help but feel a little guilty. More than that, though, she felt sorry for Derpy. It was no secret that she was a single mother, but hearing that request made her wonder if Derpy had anypony to help her. If she didn't, then Twilight was going to make sure she did.

Twilight's expression softened as she leaned over her and gently placed her hand against Derpy's side, rolling her over to lay on her back and face the alicorn above her. Twilight leaned down further and planted a kiss on Derpy's lips, holding her there for several moments before pulling back and looking straight into her eyes. "I promise I won't," she swore before taking Derpy's hand into her own. She then hilted herself into Derpy, giving the mailmare a moment to adjust to her girth before having her way with her.

With such a genuine gesture to comfort her, Derpy lost herself to Twilight's thrusts, encouraging her lover to plant her seed within her womb. Twilight happily obliged, pounding Derpy's aching pussy harder and harder, her heavy balls smacking into the mailmare's ass. She leaned forward, angling herself to thrust straight down into Derpy's eager cunt until her dam broke and she flooded the mailmare's canal with her sperm. Derpy's own climax followed, the pressure of her juices trying to force its way out of her stuffed pussy prompted Twilight to begin thrusting again even as both their orgasms raged on.

They weren't nearly done, though, as they wordlessly shifted their positions and continued making love into the dead of night. Twilight even took the opportunity to clean out Derpy's pussy with her own tongue, Derpy giving her a few pointers between her gasps and moans. Twilight's was no stranger to tasting her own cum, either by accident or sheer curiosity, but the flavor she got from their mixed fluids was something else entirely, and she wasn't afraid to dig in for more.

That didn't mean Twilight wasn't going to satisfy herself, though; she had to have cum in Derpy at least four times over the course of the following hours, always holding her close and running her hands all over the mailmare's body. She left no inch of Derpy's fur and flesh unexplored, from gently kissing her neck and shoulder to taking her lover's cute tits into her mouth and squeezing the little nubs between her teeth. It was the clearest Twilight's mind had been all day long, and she was taking full advantage of it to push each and every one of Derpy's buttons.

By the time they were finally spent, the moon shone high in the sky, and the majority of the village were lost in their dreams. Twilight lay across the soft grass beside the main path, Derpy resting atop her on her back. Twilight lifted her head to peer over the shoulder in front of her, finding that Derpy had already fallen asleep in her arms. The alicorn used her magic to get them both dressed and picked the mailmare up in her arms, carrying her back to her cottage and, holding true to her promise, decided to stay with her for the rest of the night.

I think she's going to be a very special one, she thought to herself, the last words to pass through her head before she drifted off to sleep

Author's Note

Derpy/Muffins was by far the most requested character to appear next. I was really looking forward to doing this one, she was such an adorable sweetheart in Slice of Life. I wanted to do something with the theory that she is very likely a single parent, as well as set the stage for how Twilight is ultimately going to handle her growing harem of mares.

Next chapter, things start to spiral even further out of control. From both sides.