I did it a few times before he said to take a break. He held his arms out, and I swam to him. He picked me up, and held me with his on my butt. As he ...alked around the pool his hand must of slipped since I felt a finger slip between my butt cheeks. I jumped when I felt his finger touch my little hole, he smiled and asked what happened. I said something touched my butt hole, laughing he said like this, and pressed against it again. Giggling I said yes, it tickles. He slid me in front of him and. Then he began to enter me. There was no tentative moves, he was in me in three strokes. He had to be at least nine inches long and I cried out as he rammed it home, his balls slapping on my body. He began steady strokes and I thrust into him, stroke for stroke, driving into him, wanting more as he picked up speed. His thrusts became for forceful and at times painful. He had unbelievable stamina and I came twice more before he pushed deep into me and slammed it in several times. I felt him pulse. Suddenly, Bill let out a grunt. Jerry looked up just in time to see Barbara's fist pumping quickly up and down on his shaft as she madly sucked on the end of his dick. Jerry thought he could almost see Bill's dick throb as he pumped spurt after spurt of cum down his sister's throat. Barbara's throat was working madly as she tried to swallow everything he was pumping into her mouth, but some was leaking out the corners of her mouth. Finally, Bill's cock slipped from her mouth, leaving a thin. I fantasize about it practically every time we have sex, but unfortunately, as soon as I cum I lose interest completely. In fact, after I cum the idea repels me. I've mentioned this fantasy to Pam, and much to my surprise it turned her on at least as much as it does me. She even tried to force the issue, sitting on my face and trying to make me lick her clean. I went into a sort of panic, almost bit her to get her off me, and she decided that wasn't going to work.I thought that was the end of.