I waved a hoof in temporary farewell to Cadance and Twilight’s friends at the foot of her castle, watching them head off to the spa together with a bit of wistfulness twisting in my chest. As much as I loved coming to visit my sister in Ponyville, I did wish that we were going with them, rather than being left behind to 'catch up with each other'.

At least there, I'd be getting pampered and massaged. Maybe by those two cute spa ponies... How much would it cost for a happy ending there? Allowing myself a little daydream about matching blue and pink bodies wouldn't hurt, would it? Cadance and I had an arrangement – I got one extra mare per month, and she got one extra stallion per month. But could she make an exception for me if it was two at the same time ... especially if it was just a hoof-job and maybe a little bit of suction?

That seemed a lot more fun to me than 'catching up' with Twilight. As great as Twiley was, and as close as we were, that closeness actually ended up being part of the problem.

She was a gossiper, and I was the only one who knew it. Despite how well she got along with her friends and even Princess Celestia, I was the only one she actually seemed to feel comfortable unloading her gossip cannon with. To all the others, Twilight’s gossipy streak was a dark secret they'd never know about. Or maybe someday they'd find out the hard way when Twilight really opened up to them. May the Goddess have mercy on their souls if that should ever happen.

I half-listened and nodded along as she went into the usual unending babble about whatever quirky things her friends had done recently. The new headmare of her school had apparently gone through a tough time trying to find a new guidance counselor, and it was all Trixie's fault – blaming things on Trixie was a common theme to Twilight's gossip. The Apple family apparently believed in some mythical thing called the 'Great Seedling' – not surprising. Fluttershy had caused a fuss around town after ignoring her little white bunny – this time it was somehow Zecora's fault. More and more stuff of that sort. All of it only vaguely interesting and having nothing to do with me, no reason I should care, but I stifled my yawn and went along with it just the same. Twiley needed to vent like this, and I was the only pony she could do it with. I might not like my sister's gossip very much, but I do like my sister, and this was a relatively easy way I could make her happy.

“... And she didn't even bother hiding it,” Twilight continued. “Right there in the middle of the very interesting factory tour, she asks Cheese Sandwich for a 'private tour' of the broom closet – the broom closet! – and then the rest of us have to listen to her screaming 'Yes! Cheese me, daddy!' for like half an hour before they finally come out all sweaty and try to pretend like nothing happened in there. Can you believe her?”

Wait ... now that was kind of interesting. “Hm? Believe who?” I asked innocently, trying to pretend that I hadn't ignored more than half the conversation already and trying to pretend that my sudden interest didn't have anything to do with wanting to experience just what Cheese Sandwich – whoever that was – had experienced.

“Who else?” Twilight snorted, just like she used to when she was a little filly. “Rainbow Fucking Dash, of course. Emphasis on the 'Fucking'. I swear, holding the record for 'fastest pony in Equestria' isn't enough for her – she apparently wants the title for 'sluttiest pony in Equestria', too!”

I stared at my sister, blinking. “Really? I would have never guessed...”

“Well, of course she's not going after you. You're married. And at least I was able to get through to Rainbow enough that she has some standards now. She'd never do that to Cadance, and she values loyalty way too much to make herself a homewrecker.” Drawing conspiratorially close now that she had a really juicy secret to share, Twilight all but whispered: “Soarin would know, though. And Mister Breezy, and both of the Flim Flam brothers, and Big Macintosh, and Fancy Pants”— her voice steadily grew until it was almost a shout —“and the entire Baltimare hoofball team, when they were here for an away game. And that's just the ones I know about, from just the first year I knew her! About the only eligible bachelor she won't lift her tail for is Fluttershy's brother for some reason. Not that I blame her. I mean, have you ever met Zephyr Breeze? I don't know how his parents managed to raise him without giving up and putting him up for adoption at some point. Did you know that he once...”

I tuned her out again as her gossip engine switched to another track. There was now something much more interesting to think about. Rainbow Dash the super-slut, hm? Brief visions of her flashed through his head. Tightly toned blue flanks with the subtle grooves of firm muscle underneath the fur. A rainbow tail raised just high enough to give tantalizing peeks underneath. Her tight little body squeezed into a form-fitting Wonderbolts uniform one size too small...

Oh yes. I knew exactly where I wanted to spend my one free pass of the month now. After all, it would be irresponsible of me to believe what Twilight said on mere hearsay, wouldn’t it? I'd have to see for myself before believing it. Just to be sure. As they taught us in the Royal Guard, 'Trust, but verify.'

“... Not like Rarity, though. I've been telling her for years that she needs to do more than just string Spike along with the occasional kiss or little flirt. Even when Spike finally got some action with Gabby, it still didn't occur to Rarity to try doing it with him – she tried to lure him away with gem caves and board games! And did I tell you about Quibble Pants's new marefriend? Now that's a mare who knows how to keep her special somepony interested! Rainbow wouldn't go into much detail – she's still a little peeved she didn't get another chance to role-play with her favorite convention fuck-buddy – but from what I hear, Clear Sky could swallow a full-grown stallion nuts and all. And she does anal. Which reminds me ... you'll never believe what Pinkie Pie did at the popsicle stand last midsummer fair, but it's the reason we won't be having another popsicle stand again any time soon.”

Now that I had something to look forward to, listening to Twiley's gossip was even more difficult to sit through, but I persevered. Her gossip made her happy ... and maybe soon it would help make me happy, too.

When Cadance and the others came back, all of them looked amazing. Their manes shined in the light, their coats practically glowed, and there was just something about the way they moved that said they'd found a way to really relax. Could anyone blame me for watching the way Pinkie Pie jiggled when she bounced, for wondering how soft Fluttershy's shimmery fur would feel, for appreciating the broad curves Applejack's massive assets, or for enjoying Rarity's carefully curated beauty? Certainly not Cadance – I had her permission to look all I wanted, and even so, I ended up looking at her more than any of the others. How soon could we get a little alone time for me to experience her freshly pampered and lightly lotioned body? Maybe I'd eat her out tonight ... her pussy would probably be so fresh, clean, and smooth after the spa trip. I wondered if she had splurged for the happy ending treatment.

Once they all filed back into Twilight's study, though, it became clear ... no Rainbow Dash. Why wasn't she with them?

“Did you have a nice time catching up with Twilight?” Cadance asked, coming in to give me a quick peck on the cheek.

I slid my hoof down the side of her neck as she did, enjoying the feel of her velvety, freshly groomed fur. “Yeah, it was great,” I said, only lying a little bit. Then, as casually as I could manage, I added, “Where's Rainbow, though? Didn't she go to the spa with you?”

Rarity answered before Cadance could: “Oh, of course not.” She shook her head ruefully. “Even though her rainbow mane would look fabulous after a little treatment. Can you just imagine it?”

“I think she went to go practice flying by the windmill,” Pinkie added. “She said flying's really important.”

Applejack snorted. “That's puttin' it nicely. I think her exact words were, 'You'll never catch me doing that frou frou junk! I've gotta go bust some moves by the windmill. Later, losers!' Of course, we all know she goes to the spa when nopony's watchin'.” A few giggles passed back and forth between them.

“How horrid!” Rarity held her hoof up to her forehead. “One would think she'd have slightly better manners than that.”

“Enough about Rainbow Dash,” Twilight said, almost dancing in anticipation. “We're going to be having some very special Royal Cake! The first time Cadance and I have baked together since I became a princess, too!”

“Don't worry, everypony,” Cadance said. “I'm only going to let her help me with the frosting.”

“Just like when she was my foalsitter way back when!” Twilight beamed.

Cadance gave her a wry smile. “Only, I'm hoping you won't 'accidentally' spill as much of the frosting in your mouth this time...”

“Yeah! Leave some frosting for the rest of us – and put most of it on my slice!” Pinkie giggled for a moment, but then froze, her eyes going wide as if she was suddenly terrified. “Wait! Do we have to wait for Rainbow to get back before we eat? I'm starving! All the spa had to eat was eye cucumbers!”

Rarity patted her on the shoulder comfortingly. “Well, it would be terribly rude of us to begin without Rainbow. Someone will simply have to go fetch her.”

Almost everypony looked toward Fluttershy. She shrank down, squeaking out, “Why me?”

“Well, you could fly there faster than any of the rest of us could walk,” Applejack said. “'Cept maybe Twi or Cadance, but they've got to stay here and bake.”

“I'll go,” I suddenly volunteered. It would be the perfect opportunity to get a little alone time.

“Oh thank goodness!” Fluttershy's apprehension quickly deflated, and she took the opportunity to slip back behind Cadance, where nopony would notice her again.

Rarity objected, though: “Oh, but you've only just arrived all the way from the Crystal Empire. You must be exhausted! We couldn’t possibly ask you to go so far now.”

“I just sat on a train for six hours, and now I've been sitting here in this castle.” I got up out of my seat – as comfortable as it was – and made a few theatric stretching motions. “It'll do me good to get out and stretch my legs a little bit.”

Cadance gave me a knowing look. As usual, she could see right through me. Had somepony already told her how slutty Rainbow Dash apparently was, or had she been able to tell just by looking at the other mare? As the Princess of Love, her powers of perception in matters like that were nothing short of extraordinary. “Well, don't take too long, dear. Or there might not be any cake left by the time you get back.”

I grinned in a way I hoped she'd interpret as 'thank you'. Because of the way she always seemed to be able to see right through me, I'd never dream of doing more than the allowed one indiscretion per month. But then again, I had that very same understanding nature to thank for her allowing me that in the first place. Such a good wife! I added a bit of salacious eyebrow wiggling to the smile I was giving her, hoping she'd get my 'And later tonight I want to eat you out until your moans wake up the whole castle' message, too. If this went the way I was hoping it would, I'd have a lot to feel grateful to her for, and I'd want to show it the best way I could.

Now I just needed to go out and find Rainbow...

She was by the windmill, but she wasn't practicing moves – she was napping on top of a small cloud, visible only by the bit of rainbow tail hanging off the edge.

“Rainbow Dash!” I called out. “Hey Rainbow, are you up there?” Of course I already knew she was, but it seemed like the polite thing to say, just in case she wanted to ignore me and pretend she was nowhere around. There sure wasn't anypony else around out here, even though it was a pretty nice day outside.

But it turned out that being ignored wasn't something I'd need to worry about. Rainbow Dash darted down from the cloud in a rainbow-colored streak, doing a few flips in the air before coming down to a fast and dramatic landing right in front of me. “Not bad, huh?” she said with a smirk.

Was she ... was she showing off for me? Or would she have done that to impress anypony who came looking for her? I had to admit that the gracefully confident way she moved was really nice ... part of what made her so attractive. Nodding agreement, I decided to try my most winningest smile on her.

Her tail immediately shot up behind her, and she blushed a little bit.

Well, what do you know... It seemed like Twilight was right about her. I gave her even more of that smile. “Hey, so, um... This might sound a little random and out of nowhere, but is there any chance you might want to—”

“Drag you off behind those bushes and have you fuck my brains out?”

My jaw dropped. I didn't think I'd been that blatant about my interest, had I?

“Heck yeah I would!” She laughed. “But wouldn’t Cadance be mad? I learned my lesson about messing with alicorns when I fooled around with that Flash Sentry guy in the guards. Apparently, he 'belonged' to Twilight, even though she'd never done more than bump into him a couple times. And Twilight's got some crazy magic, let me tell you. After what she did to me, I was walking bow-legged for a week!”

Oh... Oh wow... Apparently, there were a few things in Twilight's life that she didn't feel like gossiping about. Those were some pretty big omissions! I struggled to get past the shock, stop thinking about the implications of what Rainbow said, and find some way to explain the situation instead. “I, um... Cadance and I have an, um...”

Rainbow nodded along, apparently already understanding me perfectly. “Oh, you've got one of those kinds of marriages, huh?” She grinned broadly. “Awesome! Maybe I'll get a piece of her later, too! Let me tell you, you've never been fucked until you've been fucked by an alicorn's magic cock!”

It was my turn to blush this time. “Actually, um...”

“Oh, right.” Rainbow laughed again. “I guess I don't have to tell you that, do I? I bet Cadance could even teach Twilight a thing or two about that kind of spell!”

Not the kind of thing I wanted to talk about at the moment. “So, um...” I glanced over toward those bushes she'd mentioned.

Grinning even more, Rainbow rushed up to me, grabbed my hoof, and did literally drag me off behind the bushes.

She threw me down onto the soft grass, and almost before I'd hit the ground, her muzzle was already down between my legs. Her mouth went straight to my sheath, and she wasn't shy in the slightest about venturing her tongue wetly inside, already trying to tease my tip out. With surprisingly gentle hooves, she massaged my balls, adding to the all-around stimulation.

Wow ... she was actually really good at this! My cock began to emerge right away, eager to come out and play with her. It didn't see the light of day, though – not yet. Every little bit that came out went straight into Rainbow's mouth.

She looked up at me with pure adoration in her eyes as it began to grow and really fill up her mouth. Her tongue darted all over my half-grown tip, teasing her way to having more to play with.

And my body was happy to give it to her. Surging toward full hardness, my cock grew to the point where it touched the back of Rainbow's mouth. She swallowed it down without so much as a blink, her undulating throat pulling my tip ever deeper.

One of her hooves left my balls to get jammed up between her own hind legs, fiddling away back there. Not that I minded, of course. Cadance might have been one of Equestria's foremost experts on fellatio, but even she couldn't quite match the eagerness with which Rainbow gulped down my growing length. The way her deep pink eyes looked so needfully up at me, the way her tail rose up behind her as she so obviously enjoyed every moment of it, and of course the soft pulsing of her throat ... it was all incredible. I reached a hoof down to run through her rainbow mane and brush a little of it behind her ear, and she pressed her lips down against my sheath even more firmly, as if desperate for even more length to suckle on.

Only after my cock had hardened to its full size did Rainbow actually pull back away from it a little bit in order to start bobbing her head up and down. And still she stared up at me with those amazing eyes of hers, looking up at me like she was unfathomably grateful for the chance to have my cock stretching out the inside of her throat. Did she even need to breathe?

Apparently not. She just kept slamming her face down onto my sheath over and over like she could do it all day. Maybe she could. I sure wouldn't doubt it after seeing her in action! And I was in no hurry to get anything else – the wet warmth of her throat rippling over my cock was incredible – easily one of the best blowjobs I'd ever gotten, and that's saying something when coming from a stallion who's married to the Princess of Love!

I would have been a happy enough stallion if Rainbow just kept up what she was doing for as long as it took ... but she wanted more than just that. After giving my cock a last few slurps all the way down from my tip to my base, she finally came up for air, gasping deeply. Not that it seemed to incapacitate her for even a moment, though, because even as she breathed, she hopped up on top of me, planting her wet pussy on top of my spit-slick shaft. She wiped her lips with a hoof and grinned down at me. “Think you're ready for the real thing, big boy?”

Slowly, I looked her up and down, taking in the gorgeous sight of her slim and compact body, her long lean belly stretched out right in front of me, and the cute little teats hidden down along her sleek and smooth underbelly. Her small but nicely round and very powerful thighs clenched around my sides, making her pussy glide up and down along the front of my shaft a little. Dumbstruck by the perky good looks of her little body, I could only nod.

That was enough for her. She languidly slid forward, enjoying the feeling of my cock slipping over her frantically winking slit until she was all the way up to the top of it. All she had to do was reach behind herself to line things up – which she did with impressive ease – and push her entrance down over my tip ... which she did with even more impressive ease.

I gasped a little as I felt the tip of my cock enveloped in a new warmth, even more intense than before. Despite how easy it was to slip into her, her pussy squeezed down on my cock like I'd never felt before. “You're ... you're so tight!” I said, through clenched teeth.

Rainbow planted her forehooves on my chest and slid herself all the way down to the base of my cock in one smooth, incredible-feeling motion, letting out only the slightest moan as she took me to the hilt. “Well, duh. I put a lot of effort into working out every other part of my body – you think I'm gonna slack off when it comes to the most important part?” Her internal muscles clenched down on me in a way that had to be intentional, squeezing every bit of my length.

And she didn't stop squeezing when she started moving. It seemed to come so easily to her, rocking her hips back and forth on my lap while clutching down tightly on the cock embedded halfway through her body. It brought a whole new intensity to the experience I'd never before thought possible. I would have been scheming for ways to have Rainbow give Cadance sex tips ... if my mind wasn't already overloaded from the sight and the feeling of that tight blue body writhing on top of mine.

Although she'd started out smooth and steady, Rainbow's rhythm soon grew faster and more erratic. She gasped and missed a beat, then picked up again right where she'd left off, her pussy squeezing down on me even harder. Her hooves slipped off of my chest and wrapped around the back of my neck instead, and her hips started bouncing so quickly it was more like trembling in place than actual fucking.

Wait ... was she already—?

“F-fuck!” Rainbow's body went rigid against mine, her wings trembling in the air above her back. Warm wetness doused over my balls and thighs, her passion squirting all over me.

I stared in awe, instinctively reaching up to wrap my forelegs around her back, just above her slim little waist. Holding her tightly against myself, I held still and rode out her orgasm, marveling at the way her inner walls moved around my cock. They clenched and grabbed, even seemed to move up and down a little as if trying to jerk me off from the inside, trying to milk the cum out of me.

When Rainbow collapsed down onto my chest, her insides finally relaxed into a soft warmth. Experimentally I tried lifting up my hips a little, which nudged my cock a bit deeper inside her. Still a pretty tight fit, but no longer the kind of astounding pressure she'd been giving me when she was putting active effort into it.

She didn't take long to recover. Scant moments later, she pulled herself up off of my cock, squeezing her way out of my embrace and standing up next to me. She faced her rump directly toward me, the arc of her rainbow tail raised high above it and her tight little ass cheeks on full display – not to mention the winking, drooling pussy lips nestled in between them.

“Well,” she said, already impatient, “are you gonna lay there and stare at me all day, or are you gonna fill me with that nice cock of yours?”

Hastily, I scrambled up onto all four hooves ... then only two as I reared up to mount her. Sliding my chest up over her firm little ass was easy – she was a good bit shorter than Cadance, after all. And by the time my tip kissed up against the heat of her pussy, she immediately winked it open and shoved herself back against me. No wasting any time with this little firecracker! I went along with it, thrusting forward at the same time, pushing my cock back up inside her until my balls squeezed up against her trembling thighs.

That was when she finally broke, squeaking out an adorably girly moan at the point when she was stuffed completely full.

And after that, it was all over for me. My body started moving all on its own in response to the sound of her little squeal, urging me on to tease more of that out of her. With my forelegs gripping tightly against her trim little waist, I pounded into her as firmly as I could, over and over again, in a heady rush of lusty urges that could only end one way. Each thrust sent a wash of her delightful warm wetness over every bit of my cock, and her pussy was getting tighter and tighter as she squeezed down on me again.

Rainbow wasn't squeezing constantly like she'd done before, either. She'd relax a little every time I pushed into her, then clench down hard, seeming to fight me when I drew back for another thrust. That pattern made it so much more tempting to push, push, and push at the end of every thrust, which seemed to drive her crazy, judging from the increasingly desperate pitch of the little moans she gasped out.

But it was driving me crazy, too, pulling me closer and closer to the inevitable orgasm. When I felt the increased tightness around my tip that meant I must be flaring out inside of her, I knew things had gone too far.

With a heartbreaking effort of will, I forced myself to pull out of her. A shudder ran through me as my flare passed between her tightly-clenching inner walls.

And just as I was about to pull my swollen tip completely out of her, Rainbow turned her head, looking over her shoulder at me. The unabashed need in her eyes stopped me perfectly still for a moment. 'How could you do this to me?' her face said. 'Put it back in! I need it inside me!'

But no. No. Part of my arrangement with Cadance was that neither of us would be having children with anypony else. I had to pull out. Steeling myself for the impossible, I yanked my cock the rest of the way out of her, making both of us whimper a little with unsated need.

Rainbow, though, wasn't the type to just stand there and whimper. The moment I slid off her back, she whirled around and tackled me back down against the grass. Before I could protest, she plunged herself right back down onto my cock.

My head swam with the intense and unexpected feeling of my cock rushing back into the warm embrace of a mare. My eyes drank in the sweet sight of Rainbow's tight little body quivering with need. My hooves shot up and grabbed the slight swell of her hips – not to push her away, but to instinctively pull her down as my hips thrusted up into her, getting my cock as deep inside her as it could possibly go. My flared tip pressed right up against the entrance to her greedy womb, and I knew all was lost.

With a foregone mental apology to Cadance, I thrust up into Rainbow. And again. One more... Yes!

My whole body jerked against the ground as the first thick stream of cum shot up into Rainbow's pussy. Her inner walls clenched and churned around my shaft, working with me to help pump more and more of it straight into her waiting womb, and to hell with the consequences – nothing in this moment could override the absolute instinctive imperative to breed the perky little blue mare pressing herself against my lap. Nothing mattered more than filling her hot pink insides with a flood of white. I came harder than I had in years, spewing every drop I had to spare up into her alluringly tight body. And not a drop went to waste: her pussy squeezed against my shaft and her body soaked up my cum greedily.

Finally, I had no more to give, and I went limp, lying against the grass and struggling just to breathe. That was when the full gravity of what I'd just done finally percolated into my brain. Oh shit, oh shit! What was I going to tell Cadance? Would she understand I hadn't meant to? Was that enough? Maybe we'd get lucky and Rainbow wouldn't get pregnant. But what if she did get pregnant? Cadance had always been understanding and willing to forgive any problem in the past, but surely she had some limit to that. And if she had a limit, surely this was it! There was no way she could forgive me for impregnating one of my sister's best friends!

Rainbow seemed far more relaxed about the whole affair. Even blissful, perhaps, as she sat there on his lap with my slowly wilting cock still inside her, my potent cum soaking into every last bit of her inner depths.

Finally, when my cock was almost completely retreated into my sheath anyway, Rainbow lifted herself up. Only then did her pussy start to leak out some of the white, creamy filling she'd just been stuffed with. Smiling, she held a hoof out and helped heft me back up onto my own hooves.

I still stood only shakily, though, my head still spinning with the possible ramifications of what I'd just done. “R-rainbow,” I managed to mumble out. “I ... I came in... Inside... If – if you get pregnant—”

“Relax!” Rainbow laughed, losing patience with my stuttering. “You think a mare who gets around as much as I do wouldn't make sure she took her potions on time? If I ever got knocked up, I'd be off of the 'Bolts for months. You're safe with me – all that load is ever going to turn into is a nice squishy-creamy feeling on the inside.” She bit her lower lip slightly. “Fuck I love that feeling so much. Mmm...”

“Oh...” I stared at her, the great burden of worry slowly lifting away from me. “So ... time to head back to Twiley's castle, then? They're making cake.”

Rainbow grinned savagely. “Sure – first one back gets to fuck your wife!” Without waiting for me to respond, she shot off at the speed of light, leaving nothing but a rainbow blur – and a few white droplets – behind.

In no particular hurry, I began lazily trotting back toward the castle. After all, Cadance deserved to have a turn of her own. And maybe if I ended up getting really lucky, they'd even let me join in...