(All characters in this story are at least 18 years of age.)
*
..... We continued kissing as our mutual desire rose and once again I was struck by how my sister's new lasciviousness had taken hold completely under my encouragement; her slim fingers sought out her clothed clit without the slightest hesitation and when I took hold of her sweatpants and began to tug them down she eagerly lifted her arse clear of the seat and helped expose her naked, sodden cunt once again as if it was the most natural act in the world... The seal of our mouths never broke contact once.
The atmosphere in the car was hot and oppressive as my sister's sexual musk perfumed the air and we wrestled the oxygen out of each others lungs, but although I'd only begun this perverse heavy petting to tease my sister with the intent of stopping short of letting her cum I couldn't resist letting events unfold to their climax. Besides, my sister was my possession now, my little fuck puppet, and since I enjoyed the sight of her pretty face contorted in ecstatic portraits I felt that I deserved this indulgence. She was squirming around in the car seat, her slender legs splayed as wide as the pants round her knees would allow and I broke the kiss so I could watch her frigging herself, fingertips punishing her already abused clitoris, her hand a white blur in the gloom of the car's interior. Satisfied that she was shamelessly lost to self-gratification, I violently pulled her head back as far as I could by her hair and lent forward to bite the side of her neck quite sharply...the lesson had to be reinforced... pleasure is to be accompanied by pain.
My slave slut gasped with surprise but I felt her hand work her clit with renewed vigor and being a kindly brother I moved my free hand to her crotch noting the heat radiating from it and easily slipped two fingers inside her tight but well-lubricated cunt. Still nipping at her neck I began to fuck her with my invading digits and her body quivered in time to the pace I was now setting. She was panting hard but still managed to get the words out in ragged bursts... Words that drove me to pound at her swollen and sodden cunt. "Fuck me, Sir, make me cum... I'm your pain whore... make me your slut... let me cum again for my Master... I'm yours... please, can I cum, Sir?" I responded by lowering my head to the swell of her petite and perfect breast and biting on the stiff nipple forcing its presence through the fabric of her top, enjoying feeling the hardness of it between my teeth as I chewed the sensitive bud. My sister thrashed around in wanton abandon as the conflicting sensations of agony and ecstasy flowed over her and produced the exhilaration she embraced so fully.
The frenzied way she was thrusting her thighs against my hand to force my fingers a little deeper inside her young body told me she was past the point of no return again and so, giving her breast a final bite, I dragged my teeth off her extended nipple protruding through the saliva soaked cloth and whispered in her ear. "Right, slave, prove you are mine, cum hard for your Owner." "Yes, Sir," she sobbed as she bucked uncontrollably, arching out of the seat and hitting the steering wheel as her body convulsed with spasms of pure electric rapture. I pulled her face to mine once more and stifled her incomprehensible words of passion with another kiss... sharing her climax with this simple intimacy that seemed to prolong her orgasm until she went limp in my arms.
I thought for a moment she'd actually passed out due to the intensity of the moment, but when I looked down into her angelic young face, the sheen of sweat shining in the darkened surroundings, I noticed her eyelids flicker and a slow smile of post-coital content spreading that put my mind to rest.
However blissful grinning seemed to be all she was capable of; this latest orgasm had sapped the last of her physical strength and I was eager to get her safely back into the house where my Ownership of her was complete. Therefore I exited the passenger side of the car quickly and gathered her up in my arms to carry her indoors, the carrier bag full of purchases my sister clutched possessively as she allowed herself to be transported the last few feet of our shopping expedition. As I approached the house with my light burden I couldn't help noticing the curtains twitch slightly in the upstairs window of our next door neighbours and I wondered idly if our dalliance in the car had been observed. I was more shocked to realize that I didn't really care if we had been.... a dangerous attitude that I'd have to be careful of in future. Still, it was fairly dark and it wasn't even as if I knew who lived the house next to us anymore, the family who'd lived there whilst I was growing up having moved out whilst I was living independent of parental guidance. Hopefully they wouldn't poke their noses in, even if the sight of a stranger carrying their neighbours' bedraggled daughter in would warrant it. We reached the front door without being challenged and I managed to find the keys and unlock it without disturbing my sister's happy snuggling against my chest; once over the threshold I maneuvered my precious load into the living room and gently laid her semi-conscious body down onto the sofa to recover from the exertions of the day.