"What, to each other?", someone asked. There were quizzical looks all round. "No, no.....they both want to take their turn together, as opposed to doi...g it on their own". There seemed to be no objection, so the decision was made to allow that to happen. "And Mark wants to ask you if I can be left out of it when he takes his turn", she blurted, looking a bit red in the face. "He wants me to go out while he asks you, and I said I would". She was being fair and grown up "out loud" so that Mark. He had often wondered what it would feel like fuck his sister, but also knew that it was wrong to have a dream like that. However, when he first caught her watching him at the pool, he knew that it would become a reality some day. Today, was that day. The wet warmth of her crevice surrounded his long stiffness. He could feel the soft flexible pink barrier slide along his cock as he slowly moved in and out of his sister. He consumed her as much as she consumed him. It was a mutual feeling. "I sulked at her insult but didn't speak up for myself. My mom just smiledat her and said, "Now Madison you just be good while we are gone and obeyMark. He is your older brother. He's in high school and can takeresponsibility for you"Minutes later my parents left. As soon as they were gone Madison got onthe phone with her best friend Abby. I didn't want to hear their sillygirly-girl conversation so I went into the living room to watch t.v. bymyself. After a while Madison came and sat. Although they were young, they were quite cute in a sort of rough naughty way, so I whipped my cock out and started having a wank while watching them. Some bloke appeared over the fence and told them off, at which they sauntered off giggling. I went to the bedroom at the front of the house, in case they went that way and to my delight they did, so I carried on wanking. They were just milling about, generally being quite naughty, banging on fences etc then one of them kept lifting her top up and.