This is the 6th Chapter in a much longer story. For your maximum enjoyment it is suggested you read Weeks 01 to 05 first.
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As the new week dawned I was all too aware that our summer break was ending in seven days and the amazing time that I had spent with my sister Mary over this exciting six-week period was going to end.
How we would manage our relationship - this illegal, incestuous relationship - in the future was starting to bear down on me. I knew I loved Mary completely, that I wanted and desired her all the time, that my life would be incomplete in the future if she was not central to it. And I knew that she was my sister and that the world would not approve of our relationship or condone what we were doing.
We found time to be together whenever we could. In the evenings, when our parents were around, Mary would tease me by engineering ways for us to rub our bodies together as we passed in the hallway, she would grab opportunities to kiss me and grope my cock when we were clearing away the dishes and she would contrive to flash me views of her pussy or breasts whenever she could do so safely. It was such an awesome time; I was almost permanently erect and drooling with pre-cum.
I was desperately in love with her and would never be able to love anyone else so deeply or so completely. And she loved me too, and all her wanton behaviour was reserved just for me.
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I had a shift at the supermarket that I worked in for my summer job on the Monday morning but had the afternoon off before I had to go back in the evening. I was looking forward to getting home so that I could make the most of the time that Mary and I had left before normality returned at the end of the week and we would both have to return to college.
Arriving home, I walked into the kitchen and saw a note that Mary had left on the table for me. "Hi Adam" it read. "Lunch is in the fridge. I've just popped out but will be back very soon. Mary xxx." I smiled in gratitude as I was really hungry, so I collected the sandwich, made a coffee and took the plate and mug into the lounge so I could play some music on the hi-fi whilst I ate my lunch.
I had not long finished and was laying on the sofa, eyes closed and humming along to the music when I heard the front door open and close and Mary called "Hi, I'm back. I'll join you in a few minutes." I then heard her bedroom door close behind her. I was toying with the idea of getting up and going to join her in her bedroom, but the fact that she had said she would join me and also that she had closed her bedroom door made me think better of it.
I was very happy to wait - Mary never ceased to amaze me every day; always thinking of new ways to surprise and excite me and to keep our regular sex sessions fun and fresh. I was feeling very randy after a weekend of her teasing me mercilessly whenever she could and my cock was already half erect in anticipation.
The lounge door opened and I turned my head to look as Mary entered. My heart leapt in my chest, my throat became immediately dry and my mouth dropped open. "Oh my God, Mary..." I spluttered. She had done it again - no matter what I was expecting and how prepared I was for her to surprise me, she always ratcheted things up further than my imagination had been able to go.
She was wearing one of my shirts, which was far too big for her frame except where it passed over her huge breasts, which were straining against the fabric. She had a belt cinched tight at her waist, causing the shirt to mould to her hips as it flared out over her hips and butt. The shirt had the top four buttons open, revealing the start of her deep cleavage and showing the white lacey top trim to her bra. Beneath the shirt I could glimpse the top of her pale stockings and she was wearing, for the first time that I could ever remember, a pair of white stiletto heeled open toed shoes. Her hair was tied up loosely on top of her head and she had used dark makeup to accentuate her eyes and eye lashes and had a trace of pink lipstick to exaggerate her full lips.
She smiled provocatively at me. "Do you like what you see, Adam?" she asked. "I think I can tell that you do" she giggled as she looked down at my throbbing cock as it swelled against the front of my trousers. "Oh Mary," I managed to croak. "You look astounding."
I was sitting upright on the sofa, unable to move. I could not take my eyes off her, she looked amazing. I could feel the front of my boxers growing wet and sticky as my cock leaked pre-cum in anticipation. Mary moved over to the hi-fi and, with her back to me, she leant forward so that her butt stuck out and the shirt rode up over her butt, revealing the skimpy lacey white French knickers she was wearing, with the gusset pulled tight and disappearing between her arse cheeks. I could also see the straps of her white suspender belt as they emerged beneath her knickers and clasped to the tops of her stockings to keep them tight. She changed the music to a soft, soul disc and turned back to face me.
Slowly moving her hands up, she started to undo the remaining buttons on the shirt and released the belt at her waist. As the shirt fell open it revealed not a bra but a tight teddy-style corset that fitted her breasts and body like a glove, pushing her tits upwards and together - emphasising their size and the valley between them. She walked seductively over to stand right in front of me as I continued to gawp at her from a sitting position, almost frozen in place.
Mary slowly slid the shirt off her shoulders and, as it dropped to the floor at her feet, she straddled me, with her legs kneeling either side of mine and her arms wrapped around my neck. I could feel her breasts pressing tight against my chest and I could sense her rapid breathing as her own excitement grew. She reached down between us and cradled my cock through my trousers and searched for the zip. I moved my hands to help her, opening the waist of my trousers, pushing my zip down and then lifting my hips upwards so that I could slide my trousers and boxers down and off my ankles. My cock swung upwards as it was released from my boxers and slapped into her pussy. "Oooohhhh" Mary moaned as she wiggled her hips and ground her crotch across my swollen cock. I could feel her juices leaking through her knickers and coating my prick and smearing across my pubic hairs.
"I can tell you want me as much as I want you," she whispered in an excited, seductive voice. She moved her head forward and gave me a deep, long kiss with her tongue pushing deep into my mouth.