It was two days before they really spent much time together again. The following day had been a return to the usual, exhausting training routine for Shining, and Twilight had chosen that day to pay a visit to Cadance anyway. But the day after that was a weekend, and both Twilight and Shining had the day off. Twilight, as it turned out, had scheduled that afternoon for the two of them to spend some time together - studying, she said.

He figured something was up, however, when Twilight told him - after they’d left the house - that they weren’t going to go to the library, but instead to Cadance’s house while she was out. “She’s on a trip to Fillydelphia, and I asked her if I could use her place while she was away, in case I wanted to study alone.” She levitated a key up to Shining for emphasis, before stowing it away in her bags.

“You won’t be alone, though,” Shining pointed out, frowning a little.

“Well, alone with you, in this case.” Twilight smiled. “Besides, it’s more comfy there than in the library.”

Shining chuckled. “I won’t argue with that.” Still, he wasn’t clueless. Obviously, she had something she wanted to talk about, away from everypony else.

She did, however, bring along some books, and as they entered Cadance’s living room, she levitated them out of her bags and onto the coffee table, before taking a seat on a soft, plushy sofa. “Now, where to begin…” Shining sat on a couch on the other side of the table, watching as she flipped open a book on zoology and started taking notes.

It was obvious to Shining that she was distracted, however - if only because she was a little less on-the-nose than usual, taking slightly longer to turn pages or solve problems. For most ponies this was normal, but if Twilight wasn’t giving her full attention to her studies, if her mood was anything other than complete determination, then something else was on her mind. It was not hard to guess what.

Of course, since she was apparently using the excuse of studying to put off talking about it, it fell to Shining to take the initiative, again. “Something on your mind, Twily?”

She hesitated slightly, before setting down her pen. “Is it that obvious?” She smiled, just a little.

“To me, anyway.” He matched her smile. “I’m guessing we came out here because you wanted a private conversation.”

Twilight shifted, laying on her side, her head resting against a pillow at one end of the couch. She bit her lip, glancing away. It was actually kind of odd for Shining to see her at a loss for words, especially given that she’d planned this… so Shining decided to make it easier for her. “Is it about… us kissing the other night?”

“Kind of.” She smiled, looking at him. “I… liked it.”

“You liked it?” Shining titled his head slightly. “Are you… saying you want to kiss some more?”

Twilight glanced away again, blushing slightly. “I... really liked it, Shiny.”

“...I see.” Shining frowned a little, thinking. He asked himself how much he had liked it… and he didn’t really know the answer to that. He stirred himself out of his thoughts, and noticed that Twilight was looking at him expectantly, even nervously. He bit his lip for a moment before speaking. “Like… how, exactly?”

Twilight blushed even more. “Well… I mean, it felt good physically, but it also felt good… inside. I felt really light and excited and… safe. I mean, I always do with you, but… it was even more intense this time.”

“So…” Shining had a feeling they were both going to dance around the subject until one of them came out and said it directly. “Do you think you’re falling in love with me?” Despite the blunt statement, his voice was soft, and just a little nervous.

“Not… exactly? I think it might be that I always was in love with you.” Twilight sat on the couch, before looking at him in the eye. “I spoke with Cadance, and asked her what love felt like - I didn’t tell her about us-” she quickly added on seeing his expression. “I just wanted to know how somepony could tell if they were in love. She told me there were… a bunch of different kinds of love, and…” Twilight took a deep breath. “This isn’t me wanting you to sweep me off my hooves or anything like that. What it is, is that you’re the closest to me I could imagine anypony to be. I trust you completely, and I feel like we could do… anything together, without feeling bad about it. Even kissing… or more.” She blushed.

Shining took a moment to process this. “Well… Twily, I definitely trust you, and I do feel comfortable doing… just about anything.” He frowned a little. “...Sex is a little different, though.”

“Is it because we’re brother and sister?”

Shining just nodded.

“Why?”

Shining frowned. A simple question, spoken in a neutrally curious, almost innocent tone. Twilight was like that sometimes - often the books she liked to read were matter-of-fact, and without any overt judgements, and sometimes this meant she understood something only in terms of hard data - without any kind of personal feeling one way or the other. Sometimes it kept her objective. Other times, she needed to be told why something was bad.

He also wondered if some of the romance stories she’d been reading had desensitized her to the concept. Especially the fanfiction. There seemed to be a lot of incest in fanfiction, for some reason.

“It’s… well…” Shining’s brow furrowed in thought. “Part of it’s because… inbreeding isn’t good.” He struggled for a moment to remember the technical details of inbreeding, but he found he actually didn’t know much beyond a general impression that it was something to be avoid. “It’s… something to do with genetic defects?”

“There is an increased risk of genetic defects, such as when both parents possess a rare, recessive trait and then produce a child with two copies of that trait...” Twilight’s horn lit up, and she produced a small family tree out of light to illustrate her point. “But that’s why inbreeding is frowned upon, not incest itself. Or romantic relations.” Twilight shook her head, dispelling the diagram.

Shining sighed. “I guess… it’s more of a feeling, then. Most ponies don’t like the idea of it.”

Twilight frowned. “How do you feel about it?”

“You mean, how do I feel about you?”

Twilight nodded without saying anything, and Shining looked away, likewise silent for a long moment. He glanced back towards her, and saw her still looking at him, waiting - almost desperate for his answer. So with some effort, he turned back to face her fully. “Well… I’m not really sure. I… well, I haven’t thought about going all the way, but to be honest… I’ve always been pretty comfortable hugging you and… even kissing you wasn’t as weird as I thought it would be.” He frowned. “What do you really want, though? I mean, in terms of us, of how our relationship should be?”

“Well…” Twilight chewed her lip for a moment. “I realize we can’t just be like a normal couple, and that’s not what I want anyway. What I want, Shiny, is…” She looked down, blushing. “Well… I’m probably not going to find a coltfriend anytime soon, and you’re closer to me than I could ever imagine another colt being, anyway… so I want to be able to share in that part of life. Of… having sex.” She looked back up at him. “I mean… that’s the main difference between us and a married couple, when you really get down to it...”

“Speaking of couples…” Shining glanced around, at the room itself. Cadance’s living room. “You know I’m…?”

“Yes, I realize that you and Cadance are… a thing.” She blushed. “But, she’s strongly implied she would be okay with you being with other ponies, if you loved each other.”

Shining nodded. Cadance had been more explicit with him - she didn’t condone one-night stands, but she respected love in all its forms, and didn’t like stepping in the way of such bonds. He wasn’t quite sure what she’d think of this… but she had teased them more than once about how close they were. He started to wonder if she had let the pair use her house, knowing that something like this would happen. He wasn’t the only one good at telling what was going on with Twilight, after all.

In any event, she had a point. They did seem like a couple at times. He’d certainly heard at least one pony mistake them for a couple when they were out in public. But more than that… there was something endearing about how she was, essentially, asking him for help.

Still... it all came down to whether or not he wanted to have sex with his own sister.

He got up and stepped off the couch, circling around the table to where Twilight sat. She perked up a little as he approached, then sat beside her. He took a deep breath and said, “Let’s… try something first.” Then, he kissed her.

Her reaction was immediate, letting out a happy little sound that made Shining feel both a bit of shame and a bit of a thrill. The latter feeling won out, and he pressed in, kissing her more forcefully while he wrapped a hoof around her, pulling her tight against him. She responded in kind, sloppily pressing her lips back against his while opening her mouth. Shining licked at her lips before sliding his tongue inside, and she let out a moan as her tongue pushed at his.

After a solid minute of kissing, Shining pulled back. “Now… do you want more of that? Are you really comfortable going all the way?”

Twilight’s rapid breathing and the warmth in her eyes told him the answer before she spoke. “Yes!” She cleared her throat, blushing. “Yes, I do.”

Shining looked at her for a long moment. There was one last thing holding him back, and that was the fact that, if they did have sex, it would change things. Even though they were definitely closer than brother and sister as it was, he knew that if they had sex and enjoyed it, it would change how they saw each other. Every time he looked at her, there would be that faint touch of desire, of knowing that they’d had sex and could do so again. When he heard her voice, he’d know how it sounded when she moaned in pleasure, and every time he touched her there’d be the faintest of reminders that he’d felt her body up against his while making love. If they had sex, it would no longer just be a platonic relationship.

But then again, maybe it was already too late for that.

“All right,” Shining said, scooting to the side to give her some room. “Lie down on your back, and spread your hind legs a little.”

Twilight nodded, eagerly doing as he said. Her breathing picked up, a blush forming on her cheeks as she looked at him. Meanwhile, Shining looked down at her, where her entrance was. He’d seen it before, of course, but never when she was aroused and eager to have sex with him. He could, however, see that it needed some work… and he leaned his head down and gave her nethers a lick, eliciting a gasp from his sister at the sensation.

Shining chuckled. “This is foreplay, Twily. Very important for your first time…” He paused to give her a few more licks, before going on, “Your first time should be memorable, after all.”

Twilight nodded, trying to hold still, though her leg twitched as he continued to go down on her. She closed her eyes, trying to control her breathing with deep breaths, as her pussy grew wet and started to wink. At last, Shining pulled back, straightening up - and giving Twilight a view of his fully-unsheathed cock. “You ready, Twily?”

Twilight nodded. “What about you? Should I… do some foreplay for you?”

“If you’d like. Don’t worry about that though, just focus on enjoying yourself.” He smiled at her.

Twilight blushed in response. “Thanks, but… I want to have the full experience.”

“All right.” Shining stepped forward, carefully making his way over her until his shaft hung over her face, while he rested his hooves on the couch’s hoofrest. Twilight looked at his stallionhood for a long moment - the first time she’d really examined it while it was unsheathed and eager to penetrate a mare. After moving her head around to look at it from different angles, she reached her hooves up, holding it in place while she gave its tip a few licks.

Shining chuckled a little at her inexperience, as she went about foreplay in her usual methodical way. “Why don’t you try taking it in your mouth, if you’re ready for that.”

“S-sure…” Twilight lifted her head up as best she could, wrapping her lips around the tip and gently sucking on it. Shining let out a satisfied sigh, lowering his hips slightly so she could rest her head on the couch again. Twilight spent the next few moments gently suckling him, before starting to grow bolder, licking at his tip before lifting her head up again, trying to take him in deeper. She managed to go halfway up his shaft before pulling back, before settling for bobbing her head back and forth along his length.

Shining let out a soft moan, before gently started to pull up off her. She wasn’t bad, but she was still inexperienced, and right now she was pretty much teasing him… which meant that now he was definitely ready to rut her. He backed up, getting into position above her, before lowering his front a little to give her a quick kiss. “Are you ready, Twily?”

Twilight nodded. “Yes… please mate with me…”

Shining chuckled. Even like this, she was clinical in her language. “All right.” He pressed forward with his hips, the tip of his cock spearing her entrance and pushing into her. She gasped, and cooed lightly as he filled her. To his surprise, she wasn’t quite as tight as he’d expected - he wondered for a moment how often she used certain “toys” of hers, before he pulled back slightly and the pleasure banished the thought from his mind. He pushed in again, letting out a grunt, careful not to go too deep or too fast.

Twilight moaned and gasped, but didn’t move - something Shining noted. “How’s it feel?” he asked.

“Pretty good…” She smiled at him, eyes lidded.

“You don’t have to hold still, you know. It’ll feel even better if you take part, too.” He returned her smile, before leaning town to brush his lips against hers.

“O-oh, sorry… let’s see” She gripped his barrel with her hind legs, weakly trying to buck her hips up into him. Shining thrust into her in response, timing the motion so that it was right as she bucked upwards. She gasped, “You’re right…”

Shining leaned in to kiss her again, before resuming his pace. Twilight wrapped her hooves around him, holding him close as they kissed, his thick shaft grinding inside her. He took it slow for a while, letting her get used to the new experience - and giving them more time to kiss and cuddle while they made love.

After a while, Shining straightened up and picked up his pace. He smiled down at his sister, and her glazed, pleasured expression. If she seemed distracted before, now she was mentally all but gone- no analytical thinking, no logic, no learning. Just pure, loving bliss. The thought made him flush with pride, and he leaned in to kiss her again, ready to give her everything she deserved.

“Shiny… I’m coming close…” Twilight gasped, clinging even more tightly to him. “Please… orgasm inside me…”

Shining couldn’t help but laugh a little. “It’s okay to cuss, you know. Come on, I want to hear you say it without sounding like a textbook.”

Twilight blushed. “Please… fuck me, Shiny! Cum inside me!” Shining didn’t even get a chance to respond before she kissed him hungrily, refusing to let him break the kiss. Shining couldn’t hold himself back any longer, and he slammed his hips into her, pressing forward as he started to cum inside her.

Twilight squealed, but didn’t break the embrace or the kiss. She let out a muffled moan as she started to shake, holding on to Shining as he pounded her, filling her up with his cum. It seemed like an eternity before they both came to a stop. Shining broke the kiss, looking into his sister’s eyes as she looked into his, both of them panting. Another eternity passed before either of them spoke.

“How… how was it?” Shining smiled, a little nervously.

“Amazing…” Twilight smiled up at him. “You did a really good job, Shiny…” She lifted her head up to give him a quick peck on the lips. “And, thank you… you’re the best.”

Shining returned the kiss, feeling a warmth build up in his chest. “I’m glad.”

Twilight yawned abruptly. “I’m tired all of a sudden…”

Shining chuckled. “Probably more exercise than you’ve had in a while, huh?” He stood up, taking his weight off her, pulling out of her in the process.

“Mm, I should work on that…” She rolled over onto her stomach, heedless of the cum spilling out of her pussy. “Hey, Shiny… can you lie here with me?”

“For you, little sis, anything. Not much room on this couch, though… I’ll have to get pretty close” Shining settled back down onto her, covering her protectively. “You don’t mind, right?” He smirked.

Twilight snorted. “That’s perfect, thanks…” She closed her eyes, settling into the softness of the couch.

Shining kept his eyes open a little while longer. He wondered if he’d regret this in the morning… but he was pretty sure Twilight wouldn’t. She rarely had regrets like that, not when she was pursuing something she wanted. The worst that would happen would be that she’d consider it “a learning experience.” At best… well… they were now lovers too.

Shining smiled. She was happy, that was what was important. He’d never regretted making her happy.

Author's Note

Aaaaand there you have it. My take on my favorite of incest ships, Twilight x Shining!

Planning this was actually kind of a challenge, and not just because I was working on a two-week deadline. I wanted to try my own take on the ship... which is sort of difficult when you already have a headcanon for this ship, and it's in the form of existing fics (Like Two Peas in a Pod by Flutterwhy4 and Complicated Relations by Softy8088, if you're curious). So I kind of had to come up with something else that I liked that, that I would consider headcanon if I didn't already have a headcanon, preferably something I hadn't really seen before. This is the result.

As mentioned, this was written for the April 2019 Incest is Wincest contest, which I took as an opportunity to break my writer's block... as well as give myself some needing confidence, by proving that I could force myself to write under a deadline. After a lot of effort and procrastination in equal measure, I think I've succeeded!