Half Sister, Half Wife

Cadance soon found herself back at home. Armed with a copy of the ancient tome and a freshly stamped book card, she spent much of her time studying the texts and practicing forming the spell matrix. Shiny would be home soon and she wanted everything to be ready to go for him.

Sure enough, he came. “Hey, you’re back! Did you get everything you needed?”

She nuzzled his cheek. “Sure did! The spell itself isn’t too hard to cast, it just needs more setup than others do.” She presented the tome to him, the relevant pages already selected in her magic. “See, pretty simple matrix compared to what it’ll do.”

Shining studied the spell, humming to himself as he did. “Huh, must be because of the—” He squinted at the page, “—material components?”

Sensing his confusion, Cadance revealed the ‘specimens’ her sister-in-law gave her. “Twilight said, ‘the more the better.’ But since I don’t know anypony who’s related to me, I’ll just have to use more of my own ‘genetic material’ for your half of the spell.”

Shining nodded and hugged his wife. “You’re really sweet for doing all this, you know that?”

Cadance hugged back. “Anything for you, sweetie.”

Shining held her tighter for a moment before letting go. “I’m ready when you are.”

She nodded. “Right, we just need to gather our own ‘samples’.”

Cadance sat across from her husband. They stared intently into each other's eyes. The tension in the air was palpable as they knew what had to be done and what it would lead to. Cadance broke first. Her stoic mask faltered as her maw turned upwards. She giggled, silently at first, then more audibly as she spread her contagious joy. “Shin–hahahah–Shining! Hee hee! Oh, what are we doing?”

Shining, never one to let a good sex mood go to waste, fed fuel to the fire. “I believe we were just about to jerk off into some jars so we can do some incesting.”

Cadance’s laughter grew louder and more joyous. “Haha! Really Shiny? Incesting? I know I’m not good at dirty talk either, but that was bad.”

Blushing, Shining Armor started to tease his cock out of his sheath. “Hah, yeah you’re right, but it’s your turn now! Give it your best shot.”

Growing wetter by the second, Cadance began rubbing at her snatch at a leisurely pace. Getting herself nice and warmed up as she watched her husband’s cock grow and grow. “Oh Mister Prince Armor,” She started in an overly sultry tone, “won’t you help me? I have to collect all of these samples so that I can become genetically related to you.”

Shining stifled some giggles, his body gently shook as he tried to maintain control of himself. “Oh yeah?” He replied in an equally exaggerated tone, “Why should I do something like that?”

Throwing back her head and pulling her hair back in a way that would make even a novice actor cringe, she said, “Oh it’s just terrible! I just don’t want to have kids unless they’re incest babies! Am I wrong for wanting something that’s done by like, twenty to thirty percent of equestrians and isn’t really a big deal?”

Shining laughed again, but it was tinged with a sense of awkwardness and fear. “I don’t really sound like that… Do I?”

Cadance stopped her rubbing and crawled over to her husband, bringing her collection jars with her. “Sorry about that. That might have been a little mean.” She kissed him on the cheek. “I shouldn’t poke fun at your insecurities.”

He kissed her back and brought her into an embrace. “It’s ok, I know I can get a little, uh, competitive, when I play O&O.”

Grinning like a Cheshire cat, Cadance whispered, “I’ll give you a big ‘O’.”

Shining snorted, and the two enjoyed the simple joy of the other’s presence. That was, until they noticed they were both starting to ‘cool down’ despite not having completed their mission.

“Uh oh, looks like Shining Junior is falling asleep!” Cadance said, “Guess that means we won’t do some incestin’ after all.” She pouted for added effect. “Unless…”

“Go on…”

Cadance clopped her two hooves together. “Unless I could, perhaps, give you a little help?” She looked desperately at Shining. “Haha! Oh, just kidding!” She said in a much more nervous tone. Her eyes darted up to him again in a pleading expression. “Unless…”

Shining burst into a giggle fit, his half mast cock flopped around with him. “Oh! Oh! Noooo! You can’t just apologize for poking fun at me, only to viciously mock high–school–me! Haha!” He shared more laughs with his wife until they both settled down. “Oh, my sweet dear, sweet dear precious baby girl darling sweet precious dear girl Cadance, I shall allow you to ‘warm me up’, as the commoners say.”

Bumping his shoulder, Cadance couldn’t help but snort. “Oh thank you milord! How gracious of thee to allow this lowly alicorn the honor of raising yine owne flageth poleth!” Visible spittle was produced as she exaggerated her fake Olde Equestrian accent.

Shining nodded. “Indubitably.”

Cadance grabbed his cock and started working her hoof up and down in slow pumps. “Quite.”

“Hmm mhm. Yes.” His cock slowly stiffened.

“Ahem harumph! Harumph, yes!”

Shining, noticing that his cock was now fully erect, smacked his wife’s hoof away. Though, not hard enough that it would actually hurt. “Enough! I shalt taketh this into mine owne hoofseths now, lest ye contaminate mine sampleth!”

“Oh! You’re right, you’re right! I shall churneth the buttereth of mineth owneth sampleseths!” Cadance scooted a few inches away so she could get back to her own pussy. Unlike with Shining, her snatch had only gotten wetter from all of their dirty talk.

Within minutes, the two of them had gone from ‘warming up’ to actually masturbating. Cadance teased her clit with one hoof while the other ventured gently inside her. Shining was pumping his hoof up and down his cock when Cadance turned towards him. “Like what you see? Just think, in less than an hour, we’ll do allllll of the incesting you could ever wish for.”

Shining pumped faster. “Mmm, I’m gonna knock you up.”

“With an incest foal?”

He nodded. “Oh yeah, gonna creampie you so hard once we’re both genetically related and uh…” He trailed off, looking for an appropriate end to his sentence. “Uh, stuff. Yeah.”

Cadance worked herself more. “Yup, we’re gonna do so much incest and stuff. Just like, soooooo much stuff. You don’t even know how much stuff we’re gonna do.”

“Oh? I don’t?”

“Yeah, you don’t. Once you knock me up with an incest baby, I’m gonna send a nice little letter to Twilight asking her if she’d like to join us.”

White fur turned red as he processed the statement. “Does she even know I’m into that? What if she gets the wrong idea?” He asked in a panic, rubbing harder and faster as the scarousal hit him.

“It’s kinda hard to go up to somepony you haven’t seen in over a year just to ask, ‘Hey, can you teach me a spell to do this really complex and specific thing with no questions asked?’" She outstretched a wing to hold his withers. "Don’t worry, she’s totally into it.”

Shining nodded. “It is pretty hot though. Even if it’s kinda weird because she’s my sister.”

Cadance stopped everything and shot a pointed look at him.

He threw up his hooves. “Hey, I didn’t say it wasn’t hot! Because it is; it’s just weird because I’ve never really thought about it. So it feels new, and new feels weird.”

Kissing him, Cadance giggled and whispered to him, “I’m getting close. Want to finish together?”

Shining kissed back. “Absolutely.”

Together, they worked faster, both of them recognizing each other's signs and using them to go further. At the last second, Cadance used her magic to hold the jars in place, catching both her and her husband’s cum.

Panting and feeling a strangely nice afterglow given the circumstance, they embraced and spent the next few minutes cuddling and canoodling.

Having emptied their specimens in the collection jars, they gathered them together and began casting. Cadance, having studied the spell more, began the casting. Shining joined her, using his magic to fill in the gaps as well as to connect himself to the spell. A silver light filled the space between them. It first colored the room, then formed a solid sphere of light between the two of them. Tendrils grew from the sphere, each one reaching down to a different dish. They blindly searched for the samples until they brushed up against one. Once the tentacles identified their target, they quickly grabbed it and pulled it into the central mass. As for the fluid samples, the tendrils simply drank them up like long proboscides.

The sphere grew with each sample it absorbed. Once the sphere consumed the last of the samples and had grown to maximum size, it quivered once, then exploded. Tendrils erupting from it shot along Cadance and Shining's magic trails. They rapidly reached the two, encasing them in silver shells of light as they rose into the air. The magic energy then coalesced, all tendrils not connected to Shining Armor and Cadance rejoined the central mass. Which was starting to pump more of its light into the streams connecting it to the two until it was simply one thick cord of light between them.

The light bridge pulsed and smaller lights ran along its length between them, as if the spell was transferring information between them. Streaks of light shot to both of them, though slightly more came to Cadance. She felt a growing warmth starting in her hooves and then spreading throughout her torso. The pleasant burning sensation consumed her and she didn’t feel anything else until her hooves bumped into the ground again.

She looked up to find her husband lowering to the ground as well. She gasped once the light faded and got her first unblemished view of him. “Shining, your fur is pink!”

Shining quickly came to his senses and examined his fur, finding that it was indeed pink by comparison to the pure white his fur once was. Examining it closer, it was still mostly white, but many numerous pink strands of fur now grew alongside the others, giving his fur a pinker appearance. He looked up only to realize his wife had a similar transformation, her fur now lighter in hue. “Speak for yourself.” He said, pointing at her.

Cadance looked down at herself, gasping once at her fur, and then again when she looked at her hooves. “I have feathers!” She held up a hoof, playing with the mostly-white fluffy fur which now grew in abundance from her fetlocks.

Shining nuzzled her. “Dear, you have wings.”

Cadance snorted. “You know what I meant, Captain Ding Dong.”

“Speaking of ding dongs, my peepee is hankering for a right good romp in your hooha if you don’t mind me saying so.”

Snickering, Cadance pushed him away. “That was your worst one yet.”

He dusted off his chest. “I aim to impress.”

Cadance pulled him into a kiss. Starting as simple smooching and progressing into a panting, open-mouthed, tongue wrestling match. Shining ‘won’ the match, although neither of them would count being the non dominant partner as ‘losing’.

Breaking away from the kiss, Shiny stood and looked down at his breathless wife. With a single hoof, he pulled her up by the chin and she followed, making her feel weightless in his grasp. He led her onto the bed and climbed on top of her. She moved her forelegs above her head and Shining pinned them down with one hoof. Using the other to caress his wife, he squeezed her cheek.

She gazed up at him with stars in her eyes. “Wow… Wow. You are really getting into this now.”

He gave her a tender smile. “It’s hard not to when I have such an amazing, beautiful, smart, kind wife. You do so much for me and I’m the luckiest stallion in the world for it. I love you, Cadance.”

Cadance’s heart swelled in her chest, the very one Shiny was caressing at the moment. “Awww! It’s hard not to want to indulge you when you are one of the sweetest, most thoughtful, and funny stallions I know. There isn’t a day that goes by where I don’t count myself lucky to be married to you. I love you too, Shiny.”

Shining smiled, warmly at first, then twisting into a more lascivious grin as he pulled his wife’s mouth open. She brought out her tongue, knowing what was about to happen as Shiny began to spit. Not a short violent action, like how one might use a spittoon. But a slow pooling of spit at his lips that slowly drooled down. More and more bubbled and drooped down the string between them and as it finally connected, Shiny finally let it drop fully into her mouth with a ptu!

Swallowing eagerly, she opened her mouth again only for him to do the same thing. They repeated that for a while, some spits being long and drawn out, while others were short and quick.

It was only the slapping of Shining’s cock against his belly that broke them from this routine. Caressing her cheek, Shining asked her one simple question, “Are you ready to get pregnant?”

It took a moment for her to gather herself, but when she did, Cadance looked into his eyes with love and adoration. “With you? Always.”

Shining smiled, bringing her into another deep kiss as he lined himself up with her pussy. She moaned into him when his cock tip pressed into her. He broke the kiss and dragged his tongue up along her face, starting from her chin and working his way up her horn. She moaned and squeaked as he licked each of her sensitive spots while he took his time rubbing his cock against her entrance.

With a nibble of her cheeks, Shining pushed himself in and earned a delightful symphony of whimpers for it.

Cadance was into pretty much everything, and while the new incestuous nature of their relationship elevated the experience, nothing could outshine her love for her husband. Every inch he took forward delighted her more than any physical sensations could, though, the bliss he inflicted on her was pretty darn good too.

Shining wasn’t done with her either. He cast two spells in quick succession before she could even think. Her brain froze as she felt something penetrate her now thoroughly lubed rear while at the same time Shining’s magic vibrated against her winking clit.

Squealing, Cadance arched her back, her movements being stifled as Shiny’s magic pinned her wings down to the bed. The best she could do was clamp down on him with each thrust out, though her body was doing that on its own. She tried lighting her horn but was quickly stopped.

“Ah ah. You’ve done so much for me already. Let me do the rest of the work.”

Looking up at the veritable stud inside her, the way his muscles flexed and moved with his thrusting, Cadance knew she wouldn’t last long. In one last attempt to give as good as she was getting, she softly yelled “Sh-Shiny! I’m going to cum!”

Nostrils flaring, visible steam shot from them as his thrusting picked up rapidly. His achilles heel having been exploited, he rutted her like a feral beast as he knew he wouldn’t last much longer. Pre cum started bubbling out of his shaft, oozing out in thicker and thicker jets as he flared painfully. His every instinct yelling, screaming at him to cum with his wife.

“Agh! Nnnng, fuck!” He bit down on the scruff of her neck as he pounded her with a last few desperate, powerful thrusts.

Cadance screamed, “Shiny! Shiny! Breed meeeeee!” Her voice wavered as powerful shots of white hot cum blasted into her eager womb.

He came and he came, another cupful of jizz flowing into her with every grunt and groan. He didn’t begin to stop until his wife’s belly was poking against his. With a final spurt, he pulled out of her and used his magic once more before falling with a flump next to her.

They both lay there panting like dogs, too tired to care about the sweat they’d eventually have to wash off. Cadance only realized what spell Shining used when she noticed a lack of the distinct feeling of cum drooling from her snatch. She gave an experimental poke of her belly, confirming her suspicions when nothing changed.

Kissing him once more, she said in a low voice, “You horny dog, there’s no way I won’t get pregnant from this.”

He replied in between pants, “That huff was the best whew sex we’ve had since our honeymoon. I wish I’d told huff you sooner.”

Pulling him closer, she hugged him like a teddy bear. “Don’t worry about that now. Just think about how great everything is going to be going forward.” She paused for a moment, letting him think about that before she continued, “Especially how good things will be when I’m gravid. Do you think Twilight would want a foal?”

Shining blushed furiously, “I don’t know if I should regret all this or if I should thank my lucky stars that it happened.” The two fell into a comfortable silence as they lay in bed. Thanks to Cadance, their relationship had never been stronger. Speaking of relationships, Shining was wondering something. “Hey sweetie, I know I was too horny to ask once I saw the spell and everything, but what exactly is our blood relation now?”

“Hmm. It’ll take a doctor to confirm it, but I’d say half-sister.”

“Wow.”

“Yeah. Half sister, half wife.”