The cord also rubbed on my back and the crack of my arse. This was made worse as I was feeling the effects of sunburn on my back from having no cover...ing over the last couple of days during the other walks she had made me do.While I walked around the edge of the pen, she used a wheelbarrow to bring in sand and laid a strip around the pen about 6 inches deep and 3 foot wide. I thought that this was to soften the concrete for me to walk on so as not to do too much damage to my knees and elbows. She straddled Tyrone and slowly lowered herself on his rock hard cock. I was interested to see if she was going to be able to take his full 11 inches, she had a hard time taking the 9 inch dildo that we had. All my worries disappeared as she lowered herself all the way down his shaft to his balls, I was amazed. She let out a moan as she pulled herself up off his dick; her pussy lips grabbed onto his cock and didn't let go. She lowered herself down again, this time about half way, she was. I walked out into the kitchen, on my way to the bathroom, so that I could wrap myself in a towel. I was only halfway when I heard “that was quite an orgasm you gave my sis”...... I turned round slowly, not even bothering to cover up my half erect cock. Not only was Cam, Amy’s step sister, sitting there at the main table, but 2 of her friends were to. Cam was 21 and was a bit of a known town bicycle. For a girl like her though it would have come easy. Given that, unlike Amy, Cam was 5”7, blonde,. (I later learned that he was the forty-something owner of a clothes shop in the local mall and that she'd met him when buying undies in his store). Although I was very naive, I knew this was no ordinary country walk they were on: so I was eager to follow. She'd got a short skirt on and was in bare legs, and she was teasing him by wiggling her bum and she walked, and as soon as they thought they were out of view, he started putting his hand up her skirt, touching and then squeezing her bottom.