The wolf in sheep's clothing

You really weren't sure what to make of that interaction, but at least she cured you of the strange, growing attraction you'd felt developing for her. It was a head-trip, though, and you found yourself wondering what the real Lisa was up to. Emily had been right that she was a stupid bitch, but she was still your sister. If it came down to it, you'd rather she be safe and happy than not.

You made yourself some lunch, stacking together a nice roast beef sandwich with some chips, and sat down on the couch to watch some sports highlights.

About fifteen minutes later you heard the familiar sounds of your sister coming out of her room and clomping down the stairs into the kitchen. "Hey, grab me a drink," you called out, momentarily forgetting that the woman in your sister's body was not, actually your sister.

But to your surprise, she responded with a cheerful, "Okay!" Bouncing into the room a moment later with a nice, cold can of beer in her hands. One of your dad's beers. That was not what you'd meant, since you were only twenty years old, but the beer was the last thing on your mind when you saw what your sister was wearing.

She wore a tiny little pleated schoolgirl skirt with bright white thigh high stockings and a matching white buttoned shirt that ended right below her breasts. The only thing preventing a tantalizing wardrobe malfunction was a pair of suspenders that very strategically pinned her shirt to her breasts, which squished them gently enough that the rounded bottom of each boob was clearly visible. Her brown hair was pulled into two bouncy pigtails, and her lips were covered in bright pink lip gloss.

She didn't have shoes on her feet, despite you recalling that this Halloween costume had come with a tall pair of black pumps. Apparently she'd been telling the truth about being unstable in heels? Weird thing to think about in that moment.

"Here you go, big brother!" she said without any accent, smiling brightly. She managed to make her voice sound virtually indistinguishable from Lisa, only it was pleasant.

"What the hell?" You said, and moved to stand up.

Emily pushed you back down onto the couch and hopped onto your lap, straddling you suggestively. She smelled really good. It was your favorite perfume from among your sister's collection. Her breasts were inches from your face, braless and tempting. It would be so easy to slide your hand right up under that shirt...

"Don't be mean, big brother..." she pouted. "We are going to drink this together," she ground her hips against the growing erection in your pants, grinning. "And then one of two things is going to happen..."

You couldn't believe this was happening as she cracked open the can and took a long drink, sighing deeply at the end. She—your sister, at least—was only eighteen, but you really didn't think it was the right time to point that out. Come to think of it, he wasn't really sure how old Emily actually was. Somehow it had never come up.

"Either," she said, pressing the can into your hand. "you are going to be a big meanie and leave a poor horny girl **** and alone, not to mention really pissed off..." she tipped the can up when you hesitated with it at your lips. The liquid rushed over your tongue and she smiled. "Or you're gonna let lil' Lisa here take a spin on that cock you're hiding and we can be real good friends."

Your jaw dropped. "You can't be serious..."

She smiled. A wicked, predatory smile. "Boy, I haven't had a dick in three years. I am gonna blow your fucking mind with this tight little teenage body. Have you seen this? Because I got wet just getting dressed. You cannot tell me you don't want to see how it feels to get with this body... and if it's not you, it'll be your dad, or the neighbor, or... I assume you have some friends? But I want it to be you first." She leaned down and pressed her pink lips to your neck, gripping your shirt tightly, eager and passionate. Her whispered voice was hot on your skin. "Lisa is gonna take real good care of you."

The traitor in your pants got fully hard, aching to respond to the sexy body straddling your lap, sister or no. "Fuck..." you said as she started pulling your shirt off over your head.