Succubus Sister or Taboo Corruption

When Emi and her twin brother finished university, they both got jobs in the same city. Emi was secretly hoping that her brother Colin would ask her to move in with him. She dropped hints for weeks about different things she thought would look good in a new apartment, asking him questions about what kind of apartment he was looking for, watching homemaking shows on the television. Finally, he either got the hint or arrived at the conclusion himself.

"Hey Emi, how would you feel about buying a condo together? We could share equity while we pay a mortgage instead of paying a landlord, we could decorate however we wanted and..."

Emi had stopped listening, and was already eagerly agreeing. Her cheeks burned with embarrassment, but she was excited to have him near her again. She knew that it was inappropriate, but she'd always had a crush on her twin, as much as she tried to hide it. It had been torture the last four years, only getting to see him on holidays and vacations. Knowing that they'd be sharing a space all to themselves, that she'd get to see him every day, to smell his scent in the living room, to laugh and joke with him over dinner, like an old married couple...

"Yes, Colin, I'd love to."

The condo that they found seemed perfect for them. It was at the high end of their budget, but their parents promised to help out if they ever needed it. Emi had a huge room and a private bathroom for herself, Derek had a nice room that caught the sunrise in the morning, and they agreed to split the third bedroom as an office. There was a decent living room, so they could have friends over, and a half-kitchen half-dining room that was just large enough to be comfortable rather than cramped.

"Is there anything we should know?" Colin asked the Realtor. "Like why it's so much cheaper than other condos in the same building?"

"There's one thing, but it's kind of weird. The last person to live here was only here for about six months. She said she heard voices in the walls at night. Started trying to sell it basically as soon as she moved in."

"Spooky," Emi said.

"I wouldn't worry about it, though," the Realtor told them. "Nobody else on the floor has said anything of the sort. I knew the guy who lived here before her as well, and he never mentioned anything like that."

With the help of their parents and the knowledge that the previous owner was trying to sell fast, Emi and Colin put in an offer lower than asking price, firmly in their budget, and only a couple weeks later were able to move in to their first home together.

Emi felt giddy as she and her brother unpacked their new home. She decorated and organized as much as she could while they went, filling the kitchen and living room and bedrooms. Colin seemed surprised by how into the house-making she was getting, but went along with it as he moved and unpacked boxes.

The office they would share was the only thing that distracted them. As they started loading things into the closet, they discovered a small door.

"I've heard of these in old houses," Emi said. "Back in the fifties, everyone would have a card table, so they started building little card table spaces next to the closet for storage."

"Is this place really that old?" Colin asked, bending down to peak into the small storage place. He moved his hand inside and gripped something, tugging on it as it stubbornly refused to move.

"Did someone leave us a card table?" Emi asked.

"I don't think so," Colin said, pulling hard as the object finally relented and popped out, as if summoned by Emi's voice.

They were both slightly confused to find a large and ancient looking leather-bound book with a small lock on it. Colin tried to pull the book open, but the lock stood strong.

"Hmm," Colin said.

Something about the book gave Emi an eerie feeling, vibes that she couldn't quite articulate, something scary, yet inviting at the same time, like an old pair of scissors in an antique shop.

"I don't think we should mess with it, Emi," Colin said. "At least not today."

Emi searched his face, wondering if he was feeling the same thing she was, and concluded that he probably was.

"We can put it in the old trunk," she said.

"Yeah," Colin said. "We'll call around to the local colleges or universities tomorrow, see if anyone might have a skeleton key, or maybe just want to take it from us."

"Yeah," Emi said. "It's just a book. Nothing to get freaked out by."

By the time they finished unpacking, the sun was starting to set, and they were starving. They ordered a pizza and ate it from the coffee table, watching a scary movie on the television. Thoughts of the odd book faded as they distracted themselves. Emi moved close to Colin and put her head down on his shoulder, and Colin put his arm around her, resting his hand on her shoulder. Emi smiled at his touch, thinking about how she could get used to this.

When the movie finished, they went off to their own bathrooms and finally to their own beds. Emi took off her day clothes and changed into a pair of panties and a t-shirt, before sliding beneath her comforter to savor the way her twin brother had held her.

That should have been the end of the day, but as she began to drift off, Emi heard a voice calling her name. It was strange -- there was one dominant voice, surrounded by echoing swirling whispers. It seemed to be coming from far away, but she thought it must be close as well, muffled by something, yet still clearly audible in her mind. Her eyes stopped closing, and she sat up in bed, listening for the voice cloaked in whisper. Then she realized what it must be.

The wooden floors of her bedroom were a little cold as she stepped back out of bed, the hallway dark, the living room full of shadows. She found the old trunk in which they'd put the ancient book, and lifted the lid, peering down at the tome.

"Emi," the book said clearly, the whispers echoing in her mind. "You came for me."

Her hand moved down into the trunk, then hesitated.

"Please," the book pleaded. "Don't hesitate. I won't bite. I couldn't if I wanted to."

Emi's fingers reached down and took the old book, lifted it, then dropped it on the coffee table next to the pizza box from earlier.

"I need your help, Emi," the book said.

"What help?" Emi asked aloud, wondering if she might be losing her mind. "How could I possibly help you."

"You must have noticed my current predicament," the book said. "I'm trapped in here. I need you to release me."

"You're... trapped in the book?"

"Exactly," the voice said. "I've been waiting for centuries for someone who was sensitive enough to the supernatural to hear me, someone who might be kind and powerful enough to release me from this prison."

"How?" Emi asked. "How were you trapped in a book?"

"I was cursed," the voice said. "I was engaged to a woman who I loved dearly. But before we could marry, it was discovered that she was a witch. The town gathered together to chase her away and burn her property. She came to me and begged me to go with her, as her husband. But how could I? I couldn't help the rest of the town hunt her, I still loved her after all. But I couldn't be with her either. So I sent her away. In her fury at my trepidation, she took my consciousness and sealed it away in this book. I've been here ever since."

"And I'm... sensitive enough to the supernatural and powerful enough to release you?" Emi asked.

"I believe you have a gift," the book said. "I think with just a little bit of guidance, you might be able to channel that gift and release me."

Emi shook her head and stood up.

"No," she said.

She began pacing around the living room.

"This can't be real."

"It's real," the voice assured her.

"Witches, voices in books, supernatural gifts, that stuff doesn't happen in real life."

"It's happening now," the voice told her. "It's happening to you."

She sat back down on the couch and looked down at the book.

"Tell me I can trust you."

"Emi," the voice said. "You have a power inside of you that you have yet to realize. I want to help you harness that power. I help you, you help me, it's a mutually beneficial relationship. You can trust me."

"What do I need to do?" she asked.

"You need a piece of paper, a candle, and me."

Emi took the book back to her bedroom. In her old school binders, she found a blank piece of printer paper. She took a scented candle from the bedside table and lit it.

"Place the candle behind the book so that you can read the words you'll need, then place the paper on the floor between the book and yourself.

Emi sensed an earnest anticipation from the book, like someone eagerly awaiting their favorite meal. It made her shiver a little.

"Do I need a pen or something?"

"Once the ritual begins, you won't need one," the voice said, as the book flipped open.

In the light of the candle, Emi could see the page the book had opened to. There was an ancient language that she couldn't read, next to a picture of what appeared to be a demon girl, horns growing from her head, dark leathery wings spread out behind her back, fingernails sharpened to claws, a long prehensile tail curled behind her. Emi couldn't help but notice that the face of the girl in the illustration resembled her own face.

"I need you to concentrate now, Emi. Focus on the sheet of paper in front of you. I need something from deep inside of you."

Emi closed her eyes and focused on the sheet of paper.

"I need your desires, Emi. Those sexy little secrets you hide deep away. Your taboo desire for your twin brother. Your lustful desire to be fucked and used and dominated. Draw it out, everything you've pushed down for all these years. Draw it out and let it fall into the paper in front of you. Focus it into a sigil of your own."

Emi felt fire in her cheeks as she blushed hard, but didn't resist the words from the voice. She felt those desires buried deep within, and tried to let them fall from her chest onto the paper before her.

"You're doing it, Emi. Keep going. All that holds you back, all those little pangs of conscience that keep you from taking what's yours. Why deny yourself pleasure? Why shouldn't you take what you want? Let those desires out. Let them shine bright."

With her eyes closed, she could not see the sigil appearing on the paper in front of her. The sigil and flame of the candle shone eerily luminescent in her dark room.

"Why should I deny myself pleasure?" Emi pondered aloud. "Why should I hold back?"

The wick of the candle began to dance wildly.

"You're a wildfire, Emi," the voice told her. "You can burn through anything that tries to hold you back. Anyone or anything that tries to stop you is nothing compared to your power. All the infernal power of this book is at your command. Nothing can stop you. Take what is rightfully yours. Claim what you desire."

A wicked smile appeared across Emi's face as she felt the fire rising up inside of her.

"Your lust is delicious, Emi," the voice told her, and she felt her body pulse in pleasure. "Your transformation is so close. You are so close to becoming. But you're still holding back."

She felt the sigil that she had drawn on the paper in front of her begin to burn into her forehead. At first it was just a warmth spreading through her, but after a moment it began to hurt and she gasped in pain.

"Don't fight it, Emi. The more you fight, the more it will hurt. Let it flow through you. You're stronger than the pain."

Heat and pain radiated from her sigil, pouring down her body like a warm waterfall. She curled up on the floor, bringing her knees to her chest, holding them tight. A strange pressure formed on her forehead and the small of her back, just above her ass. She clawed at the ground, her fingernails strangely sharp and strong as they tore up the wood beneath her.

"Your pain does nothing for me, Emi. I can't use it. Give me your lust. Think of him if you must, don't fight it. Let it flow."

She held her eyes closed tight and thought of her twin brother.

"Yes, yes, you're almost there," the voice said, encouraging her. "Think about what draws you to him. How he's always been there for you. That perfect body of his. That cock you desire. It can all be yours. All you have to do is go over to his room and claim him as your own. He wants it as badly as you do. He dreams of you falling in love with him, of running away together, of you bearing his children. He wants you even though he knows he can never have you. Go show him he's wrong."

Her eyes opened, and though she could not see them, she knew that they were different from when she'd closed them. Her mouth hurt for a second as two fangs broke through her gums, but the pain quickly turned to pleasure, a more intense and divine pleasure than she'd ever felt as a human.

She licked her lips as the wicked smile returned.

"Let it out, Emi. He belongs to you now."

Finally, the horns, wings, and tail burst forth, tearing her night shirt to shreds as she unfurled her new demonic body, rising to her feet. She caught sight of herself in her bedroom mirror, and was surprised at how sexy she found herself.

"You've done it, Emi. I have nothing left to give you."

The flame of the candle snuffed itself out. She looked down to see her sigil burnt into the paper she'd placed on the floor. The writing in the book was now entirely legible, though Emi had no interest in reading it.

She could feel her twin brother's presence in the room next door to hers. Her pussy was on fire as she crossed the hallway to his room, letting herself in. She climbed into his bed, and put a hand on his perfect chest, waking him up.

He was dreaming of her, so in his waking moment, he found her hand and squeezed, and she squeezed back. As his eyes opened, he saw what she had done. He shot away from her, pressing his back against the wall as he retreated from her.

"Emi?" he asked.

She smiled and he shivered.

"It's me," she said.

He shook his head in confusion.

"I read from the book," she said.

He looked clueless for a moment, before realization dawned on his face.

"Oh, sis," he said.

He crawled forward on his bed to her, pressing his forehead to hers. She saw him trying not to stare at her new body, but she wanted him to look, wanted him to desire her. Her wings and tail twitched and her sigil glowed as Colin felt the heat of her new body, breathed in her infernal pheromones, tried his best to suppress his lust as his cock grew hard in his pants.

"Emi," he whispered, his voice heavy with lust.

She tilted her head and pulled his lips to hers as her tail wrapped around his leg.

He twitched in surprise at the feeling of her tail, but his lust overpowered him. He kissed her deeper, his hands roaming her new body, enjoying her curves for the first time, feeling her breasts through her tattered top, her ass through her panties.

"You're so warm," he whispered between kisses.

She kissed him and pushed him onto his back, grinding herself against his crotch as they made out like horny teenagers. He pushed up against her, gripping her tight, wanting to be closer to her, never close enough. Why hadn't they done this sooner?

He felt her juices soaking through her panties, and wanted them off. He lifted her top up and off, taking one of her nipples in his mouth. Her fingers reached down and her sharp claws tore her panties to shreds, before she slid his sleep pants off. Her bare pussy sandwiched his cock, her juices dripping down, glistening in the dim light.

He stared at her bare pussy for a second, eyes hypnotized by lust as he tore his own shirt up and off his body. They were naked together for the first time, and the moment felt significant as he looked up at her.

"Fuck me," Emi begged.

Colin took her hips, lifted her up, then pulled her down, his cock sliding deep inside of her until it was completely engulfed by her demonic cunt. She thought his cock was perfect for her, and he thought she was perfect for him.

"Fuck, Emi," he gasped.

"Oh fuck," she gasped back.

She began to roll her hips up and down, and so did he, thrusting up in time with her as her tail danced in the air behind her. She was in ecstasy and he in bliss as the sounds and smells of their incestuous fuck began to fill the room. Both of their senses were sharpened, their pleasures elevated exponentially by the effects of her magic.

They fucked for as long as they could, his cock swelling inside of her, her pussy clamping down around him.

"Cum inside me, brother," she whispered.

He took her hands, folded his fingers in hers, holding them as he thrust faster and faster, holding back for as long as possible, wanting to be good for her, wanting to give her as much as he possibly good, losing rhythm, losing sense, hypnotized by their taboo pleasure.

"Cum deep inside me," she ordered again, and he did, warm thick cum filling her womb.

She leaned over him as his cum filled her, moaning in pleasure as she felt her orgasm rock her with infernal ecstasy, drooling as her mind went blank with pleasure. Then she felt his lips on hers, kissing the drool away. His hands weakly roamed her new body, playing with her wings and tail. She relaxed and fell against his chest, her tail whipping like a candle-flame as he played with it.

"That feels good," she whispered with a giggle.

"I can't believe you're finally mine," he told her.

"I've wanted you for so long," she told him.

"You don't have to want anymore," he said. "I'm here."

She moaned and kissed him, her tail taking his comforter and pulling it over them as she felt herself start to fall asleep atop him. Her wings fell into a protective shell around him, warm and inviting.

"Do you think I should read from the book, too?" Colin asked. "Do you want me to be like you?"

"No," she said. "I like you just the way you are."

She hugged him tight. "Go to sleep, dear brother. In the morning I want to drink your lust again."

"Yes, dear sister," he said, hypnotized by her words, eyes closing with a blissful sigh.

They fell asleep, him holding her, her holding him, and in their dreams they held each other.