"That is the hottest fucking thing ever."

Stacy's eyes snapped up to her Sister.

"What!?"

But Lina had already gotten up from her place at the table and strode over to Stacy's seat. Stacy tried too late to back away as Lina embraced her, leaning in for a gentle kiss. Stacy felt a part of her go limp at the feeling of their lips touching, and she lost concentration long enough for Lina to spin her around so that they were completely face-to-face.

"What are you doing?" Stacy whispered, frozen by her mix of fear and growing arousal.

"Nothing, just relax."

Stacy couldn't relax, even if she wasn't terrified, the sight of her sister's face descending between her legs was forcing sinful thoughts into her consciousness.

Lina licked her lips and gently kissed Stacy's leg, causing her to jump.

"Lina! Don't! Please!"

Lina grinned, looking up at her sister.

"If you want to stop me, stop me. You haven't got long."

Already Stacy could feel the thing inside her stirring, knew that she didn't have long before it was too late, yet the temptation within her remained, whispering to her, you can stop her anytime. Just enjoy it for a bit longer.

She was rewarded for her hesitation by a series of tender licks along her inner thigh, gradually inching their way under her skirt and towards her pussy. Stacy gasped, her hips trembling as she felt her insides tremble in delight.

No, Lina. Stacy lacked the willpower even to speak. Please, you've got to stop...

The kiss against her panties brought a shock to race up her spine and her body shivered. Lina cooed in glee as Stacy felt the shaft of her cock slither out of her pussy and steal control of her body.

"Hello there, handsome," Lina murmured, pulling the panties down to playfully caress Stacy's penis, causing both it and her to shudder. "I'm sorry we didn't get properly acquainted earlier, but I thought you were my sister."

Stacy had expected her body to **** itself onto Lina, but instead it lay limp in the chair as her cock was stroked like a favourite pet.

"So tell me, can you talk?"

Stacy felt her head shake itself.

Lina pouted. "That sucks. But you can control her face, right?"

Stacy's face smiled through its dreamy expression and nodded.

"Hm. Okay then, stand up for me."

Stacy was confused, terrified as her body stood obediently before walking, kneeling and jumping as instructed. What was Lina planning to do with her?

"Okay then, so you have control over Stacy as long as you're hard, don't you?"

Stacy's insides froze. Her head nodded.

"So if I wanted you to stay in control, you just have to stay hard, right?"

No!

Nod.

Lina grinned, moving in and kissing Stacy's body. Stacy was **** to watch, to feel, to taste the two of them making out until Lina broke away.

"I want you to be my boyfriend... or whatever," she said with a smile. "And for that to happen, I want you to be Stacy from now on."

Lina, what the fuck are you thinking!?

Stacy's body paused, as though it had never expected to meet an ally, let alone a close family member willing to betray their own. It leapt forward and embraced Lina, who laughed and hugged it back.

"I'll have to teach you how to speak eventually, but for the time being I'll need to grab something from the chemist to keep you in control. You might go limp if you come out with me, so we might as well let Stacy enjoy her body for the last time while I'm away."

Lina led her sister's body into her room, where she pointed to her bed.

"Strip and lay down."

Stacy had struggled with every ounce of her will to resist, but her body had compliantly disrobed and allowed itself to be tied spread-eagle across the bed, a mischievious smile on its face.

Satisfied with her handiwork, Lina sat between her sister's legs, crawling onto all fours and kissing the head of Stacy's cock. It jumped at her touch, and Stacy's body raised its hips into the air with a pleading expression. Lina giggled, her tongue waving just beyond its reach.

"Get used to living like this, Stace," she said. "Because unless we've just finished fucking, this is how it's going to be."

Stacy wanted to scream in horror as Lina's lips enveloped her penis, but the raw pleasure of being sucked combined with her own body's **** anticipation overrode her own sense of betrayal. Instead she could only moan in time with her body as her sister's head bobbed up and down between her legs, the moaning increasing in passion when she felt a pair of fingers burrow into her slit.

Lina raised her head, one hand penetrating Stacy's pussy while the other jerked her off.

"That moaning," she said. "Can you control that."

Stacy felt her body - **** to feel Lina's lips on her cock again - whine wordlessly and nod its head.

"Open your mouth when you do it," Lina insisted.

"Aaahhh~!"

"Okay," Lina said. "Now while you're doing it, try moving your lips and tongue around a bit. Try saying my name."

Stacy listened in dismay at her own voice wrapping itself around nonsense syllables, her mouth forcing itself into every shape until it found the one it was looking for.

"Lee~," she panted. "Naa~ Leenaa~"

Lina giggled, overjoyed at her success.

"Very good! And for that, you get your reward."

Stacy felt her loins melting as her cock was enveloped once more, the pleasure flowing into her, filling her being while her body repeated itself in breathy whispers.

"Lina, Lina, Linaaa~"

Stacy felt the orgasm built, felt it peak, explode and be sucked away as Lina's mouth drained her of every last drop of cum, her cock coming free with a satisfying pop. Lina kissed the rapidly shrinking head as it vanished back into Stacy's body.

"See you later, babe."

Stacy felt control of her body return, but already knew that there was no point in struggling. Her body had strained itself madly as it was sucked dry, and the restraints on her arms and legs had held fast. All she could do was let the tears of despair flow as she looked at Lina's triumphant expression.

"Lina," she whimpered. "Why would you do this?"

Lina's smile vanished, her expression going deadpan as she licked her fingers clean, gagged Stacy and stood up from the bed.

"I don't see what you're complaining about," she said as she got ready to leave. "I mean, you still get to enjoy yourself and now you don't have to worry about me running off with some freak."

She paused at the door and shrugged. "Some other freak, anyway."

Stacy lay back in the darkness and felt the cold wave of despair roll over her. She could only hope that someone - anyone - would get home before Lina. It would take her some time to catch a bus to the nearest chemist, but even if she walked there and back it would only take a couple of hours.

What time was it? When did Jane come back from work? Or maybe her boyfriend Alex would come see her? Stacy just hoped Lina hadn't hidden the spare key. There weren't many other people that she expected to find her, but she could only hope.

It seemed like barely any time had passed at all when she heard the front door click open.