Twincestuosity

"What do you want to know?" he asked her, probably calling her bluff.

She shifted anxiously, partly because she would die of embarrassment if he knew her pussy was only inches from being exposed, and because she was dying to know if he had felt anything from her the way she had felt him. He would have been asleep when she was masturbating, but maybe he dreamed about it.

"What do you dream about?" she asked. "You know, when you get your stiffies?"

That made Devin laugh, and remarkably he didn't try to deny anything. They were fairly open with each other, not to any extreme degree, but even if he didn't want to talk about something, he wouldn't flat out deny it. He eyed her curiously, taking in her appearance seriously for the first time. It was unusual for her to walk around in just a t-shirt. His male eyes found it intriguing to know what she had on underneath it, even if she was his sister. Any partially naked woman, attractive or unattractive, related or unrelated, was intriguing at the very least.

"Mind your own business Lex!" he said while simultaneously lunging playfully at her with his hands.

He had meant to tickle her, maybe, or do something innocently playful. Alexa responded by shrieking and jumping backwards, inadvertently making her t-shirt hike up above her hips for about a second. Devin was watching for that, either on purpose or instinctively, and saw her completely bare vagina. His eyes widened and locked onto it, even though the shirt fell back down to hide it again.

Alexa felt her face and neck flush, knowing by the look on his face what had happened. She had not intended to expose herself to him, for the second time in two days. But like him, she couldn't deny that something had happened when it clearly had.

"What the..." was his only verbal response. His eyes, though, were about to burn the t-shirt right off.

"I...forgot to put panties on," Alexa explained rather weakly.

Something about Devin's expression told her that his mind was churning. Of course he would be shocked, maybe aroused even, but he was staring off into nothing at the moment even though his eyes were facing her. Seeing her naked had perhaps triggered the memory of his dream last night, where he had fucked her up and down the bathroom. Maybe it reminded him of some unnatural feelings of a phantom vagina being rubbed, if this was a two-way street after all.

"Are you ok?" Alexa asked, nervously pointing her feet inward and bouncing up onto the balls of her feet. The movement probably only drew more attention to her body, but she couldn't help it.

"I..." Devin shook his head. "Yeah, I'm fine."

"I'm gonna go now," Alexa finally said and hurried out of Devin's room.

Safely back in her own room, Alexa quickly shut her door and leaned her back against it while she breathed a sigh of relief. She glanced down her body and reached her hand underneath the bottom of her t-shirt to her bare crotch. She touched her pussy, spreading the lips with her fingers, and felt how wet she was. God, she was nearly dripping! The sensation of her ghost penis was gone by now, but her own arousal lingered. She so badly wanted to masturbate in what would only be a futile attempt to satiate the sexual frustration she felt, but she was worried that Devin would somehow know what she was doing. Did that matter? She didn't think any less of him knowing that he had just masturbated. Of course, he would only be confused as to how he was aware of it, and maybe feeling it too. She couldn't risk it, not yet.

She needed to think this out, and quickly, if she would ever have an orgasm of her own again. How could she explain to her brother that she had been spying on his dreams for the past decade, and now she was sharing his orgasms too? More than just his orgasms, but if today was not an isolated incident, every sexual feeling and sensation he had.

Perhaps more telling was the unasked question she hadn't yet permitted herself to ask:

Why was I so fucking turned on by the fact that this is my own brother?

Part 2: Floodgates

Over the next few weeks, things were a bit awkward for Alexa. Devin hadn't been strange around her at all. She would have thought that, after her embarrassing reveal of her private parts, he might blush or act sheepishly around her. When he did not, it irritated her a bit. Why did she have to endure this bizarre occurrence all by herself, and he couldn't give her one nervous glance?

One evening at dinner, as their parents were discussing some inane topic, Alexa found herself constantly staring at her brother across the table. He seemed to barely notice, and even when he would look up from his plate and see her looking at him, he just made a face or stuck out his tongue with chewed food decorating its surface, and then go back to ignoring her.

She didn't bother to avert her eyes as she thought deeply about her situation. Up until last night, he hadn't had any more dreams about fucking her, which had both relieved and disappointed her. For that first day after she realized what was going on, she avoided masturbating in case he did feel some small part of their seemingly one-way connection. It was very difficult, especially when he had started stroking off later that night. She would discover that it was his routine, over the course of the next few weeks.

Each time, she would be nearly paralyzed by the surreal feeling of an invisible appendage between her legs being stroked to heavenly ecstasy until she swore it exploded all over her. She would feel the orgasm as if she was having it herself, but after it was over there was no penis between her legs and no stray cum to clean up. She could only stand one night of experiencing Devin's masturbatory sensations before she gave up on her self-discipline. Once he had started in again on himself the next night, at least giving her the morning off, she closed her eyes and joined in with him. It was more difficult than it may have sounded, but trying to concentrate on two simultaneous, and quite unique, physical stimuli took some getting used to.

That first time when she rubbed her pussy while she felt him rubbing his cock, she couldn't get her orgasm quite right and she ended up frigging herself to exhaustion trying to get there along with him. It didn't happen, though she was able to finish the job afterward to some satisfaction. The next day, sometime in the afternoon oddly enough, Devin masturbated again and she was able to excuse herself to her room without making an obvious show of her difficulty walking. She actually came first this time, and when Devin spewed only moments later, she thought she was walking on a cloud it felt so good.

She was starting to learn his habits and his timing. She realized that if he went out with friends, he would usually masturbate right when he came home. His dreams weren't giving her any clues, since they had been quite boring lately, but she suspected that he was sexually attracted to one of his female friends. He was a good looking kid and some of his friends were very cute. If he stayed home or was otherwise busy for the day, he would wait until he went to bed to jerk off.

Alexa, on the other hand, usually masturbated at least twice as much as he did. She would always do it with him, of course with him not knowing what was happening, and usually she would have to relieve herself either soon after, since it felt so damn good, and a few times she had been so excited about her impending double-orgasm that she had to rub one out preemptively.

Alexa was still staring at Devin as he finished eating, and was playing over in her mind the dream that he had involuntarily shared with her last night. It was the first time she had seen herself since that first time weeks ago. It hadn't been only her, but in fact Devin had dreamt about fucking her friend Emma and out of nowhere she had joined in on the fun. That had been a nice dream, she had to admit. She had felt his arousal at the situation, his typical male response to witnessing two girls getting it on, the instant he came while they were both gobbling on his knob. She had awoken with a start, before feeling his orgasm, and was incredibly frustrated.

That was the subject of her thoughts at this moment. That frustration was becoming a real nuisance. Someone on the outside looking in might think, wouldn't the double-orgasm be enough reward to offset that frustration? Well, no unfortunately, because Alexa knew that Devin was not going to live at home forever, and neither was she. She was becoming addicted to that feeling now, which was completely irreproducible by any other means. They would eventually part ways and there would be no possibility for her to experience these unnatural voyeuristic moments unless she was in close proximity to her brother while he jerked off. The chances of that happening were slim.

If only her friend Emma knew what naughty things they had done to Devin's big cock... Alexa could see why Devin would find her attractive. She had larger breasts than Alexa, and seemed curvier all around. In the dream, Devin had seemed especially taken by her ass. He hadn't fucked it, but had thoroughly enjoyed the feeling of each cheek in his clutches. Alexa would need to find some threeway porn tonight to scratch the itch he had left in her mind.

Porn! That would be an interesting addition to the mix. What if she watched porn while she masturbated along with Devin? Maybe the extra visual stimulation would make her orgasm even more powerful!

She shook her head, fortunately not enough to bring any attention to herself. She needed to get these thoughts out of her head before she did something stupid. She was already fantasizing about telling Devin what she was experiencing and somehow trying to prove to him that it was real. But what end would that serve? It would only make him stop masturbating near her, and she didn't want that to stop any earlier than necessary. Her vagina was nearly always wet now in anticipation. She was driving herself crazy.

That night, as she lay in bed naked waiting for Devin to start his usual business, she thought about somehow branching out in her apparent ability. She didn't know how she would do it, or what she would do exactly, but if just knowing the identity of the dreamer had caused such a big change in her experiences, surely there could be even more she would discover. Maybe she could unlock the power to share her own sensations with Devin. She had been afraid of that initially, but now it was feeling more like fair play. Would that be the best way to introduce him to her strange little reality?

She built up her courage to approach him and say something to him, but before she decided what to do she felt the ghost penis stirring to life between her thighs. She groaned as she felt Devin firmly grasp his penis and squeeze it. It came to life so suddenly, she wondered what had made him so horny so quickly. She was becoming quite familiar with his usual sensations, and this was different to some degree. Even stranger was the slow, languid way he was masturbating. Usually he got straight to business, which was how Alexa liked it herself. Tonight he was teasing himself, even running his finger down his balls and touching himself just below them. Alexa was surprised how good that felt, and she ventured her own finger to the small spot between her pussy and her asshole. She had never done any kind of anal stimulation before, and this wasn't exactly the same thing anyway, but she became very curious about the subject.

Devin didn't keep fingering his taint, but eventually gripped his foreskin and just casually jacked it up and down his shaft. He was not seeking any real release. Maybe he was watching porn and wanted to make it last long enough to get through the scene. Alexa had an unfair advantage she supposed when it came to that. If she came too soon, she could just keep rubbing until it happened again.

"You better not drag this out too long," she muttered to herself, or him rather as if he could hear her.

She was trying her best to match his pace. She dipped her fingers into her cunt and smeared her juices around her lips idly. She circled her clit a few times before relenting and letting the pleasure die down. Then she was back at it again until her cunt spasmed, and she would let off for a few seconds. She was teasing herself just as Devin was, albeit with completely different methods.

It was late, and she knew their parents were fast asleep, so it was perhaps this fact that impelled her to act on her newfound courage. She would spy on her brother as he pleasured himself, maybe see what kind of pornography he enjoyed, and hopefully catch him in the act. To what end, she still wasn't sure. It could be risky, and she certainly didn't want him to stop. Or, maybe she did. Maybe a part of her knew this couldn't continue, or else she might go mad. Maybe another part of her suspected that if she clued him in to the truth, things might get even better than she thought they could be...

She threw on a t-shirt and crept out of her room quietly. Just like that time before, she had no panties on. She didn't think it mattered at this point. She was going to confront her brother about everything and see where it led. If she was lucky, they would both still be getting off in the process. She only hoped he didn't suddenly finish himself before she got there.

The whole time she tiptoed to his room, she could feel Devin's slow and steady jerking. She could sense his penis between her legs even as she walked. A droplet of her pussy juice trickled down her inner thigh in response to the stimulation. God, it was so tempting to just sit down on the floor and bring herself off. The teasing was killing her. But at least it seemed she would have enough time to interrupt him before he shot off.

Alexa saw a flickering light under his door. He had the light off and he was watching something, either TV or his laptop. She placed her ear to his door and listened for any sounds that would give him away. He could have his TV at full volume and their parents wouldn't hear from their bedrooms upstairs. That meant they could also have a conversation without being heard too.

Agonizingly slowly, Alexa twisted his doorknob until it clicked. She waited in case he heard her and came to investigate, but the muffled sounds coming from his room were steady and judging by the feeling between her legs, he was still jerking himself quite rhythmically. She opened his door slightly and peered in through the crack.

She could see Devin sitting on his bed from the side. He was staring intently at his laptop and his arm was moving exactly on pace with what Alexa was feeling. It was almost entrancing to watch his movements and feel them simultaneously on her ghost penis. If he had actually been trying to cum, she probably wouldn't have been able to stay so quiet and motionless. It was like slinking across the floor with a vibrator in her pants, only it was on a gentle buzzing setting that was more calming than anything.

Alexa opened Devin's door further until she could crawl inside. She shut the door behind her, miraculously keeping her movements silent and unnoticed, and just sat there for a moment to make sure he didn't see her. He was very engrossed in his porn, which only made her want to see what it was even more. She stayed low and tried to keep out of his peripheral vision as she moved closer to his bed. She managed to sneak over to the opposite side of his nightstand and remain there unseen while at the same time getting a clear view of his laptop.

Anal. He was watching anal sex. Alexa was a bit surprised, since she hadn't ever felt the need to seek out porn on that particular subject, but it didn't disgust her by any means. She was fairly open minded about that sort of stuff. She felt a thrill at being the voyeur once again, but this time while she was awake. She watched the anal porn along with her brother and even ventured fingering herself a bit. She didn't exactly want him to catch her spying on him like this, but whatever the result of this little adventure, she knew things would change between them tonight.

Devin began to huff and jerk faster, and Alexa could feel the pleasure increasing between her legs. The ghost penis was so hard and thick, and she could feel his grasp of it as if she was clutching it herself. She found it hard to keep her panting down, and bit her lip. She was openly masturbating though by this point, still unseen by him but not hiding her movements at all. He had only to lose his focus temporarily to notice her there only a few feet away, but he was in the zone, and the slut getting her butt pounded was about to get a hot load all over her face.

Devin let out a moan followed by a series of weak grunts as he began spewing. Alexa gasped out loud and couldn't hold back from experiencing the whole thing herself along with her own climax. Her fingers were jammed up into her pussy and she was pulling at it fiercely. Her eyes were closed the whole time but she could feel it all, the wonderful build up in his shaft and the tingling in his balls before his cum erupted from the tip. Each ejaculation was wrenched out of him with a delicious intensity, and the feel of his hot sperm landing on his stomach only made her savor the imagined taste of it.

When she had come down from it all, she opened her eyes and saw that her brother had finally noticed her sitting on his floor. With dripping cock still in hand, he just stared at her with his mouth open. Being caught like this in the throes of his self-pleasure was awkward enough, but seeing your own sister suddenly sitting in your room masturbating along with you was pretty weird. They just stared at each other for a good long while.

"What the..." Devin tried to find the words but they just weren't there.

Alexa withdrew her fingers from her sopping vagina and nervously clutched her hands together at her stomach. She smiled sheepishly at him.

"I...heard something coming from your room," she said. "I wanted to see what it was."

Devin suddenly realized the porn movie was still playing on his laptop, and he clumsily closed it while trying not to get cum all over it. His jerking hand was very slimy after that impressive load, and he had cum running down his stomach now.

"Jesus fuck," he said as he got his bearings. "What are you doing?"

"I just told you," Alexa answered. "I didn't want to interrupt you, so I just watched."

"You watched me jerk off?!" he exclaimed. "Why?"

She shrugged. "It was interesting. I dunno, I kinda liked it."

Devin just stared at her for a moment, and then glanced down to see that she was only wearing the t-shirt, again.

"What is with you?" he asked. "It's almost like you have a thing for me or something."

She smiled. That line of reasoning would work just fine.

"I guess I just wanted to know what a guy...does, you know?" She cocked her head curiously. "Is that so bad?"

Devin grabbed his previously discarded shirt and wiped his body and hand with it. He shook his head and laughed.

"You are really twisted."

"Can't argue, I guess," Alexa replied.

Seeing that she wasn't making any attempt to move, Devin just sat on his bed on top of his blankets with his softening penis dangling free. He wasn't exactly shy about it, and it seemed that his sister wanted to see it for some reason, so why not let her? She fidgeted on his floor as she was obviously trying not to stare at it.

"What's with the commando thing?" he asked finally.

"Commando?"

He nodded. "No underwear. Seems to be a trend with you."

She blushed. "I, uh...I sleep naked."

"Then why the shirt?" He seemed to be challenging her with the question.

She caught on. "Want me to take it off?"

Devin chuckled, but when she pulled her shirt up and over her head and tossed it aside, his mouth dropped open again. She was completely naked now, sitting only a few feet in front of him. He was just as naked, and even though he had literally just cum, he felt his penis responding.