I entered her gash from the rear andfucked her with long, pounding strokes with my cock.She moved back and forth, meeting my thrusts with oneof her ow.... My heavy balls were banging loudly againstthe back of her nylon covered thighs. Before long I waspumping large globs of sperm into her welcoming hole.We wanted a baby, so neither of us ever used any kindof birth control, even though I always carried a coupleof rubbers with me, but they were used only when Ifucked her up her ass. As I withdrew. I looked at my first real life boobs and pussy. She looked at her first penis and first boy nude. We both stared at each-others body until I started to get an erection. We both smiled and then started laughing as my penis grew to 6 inches rappidly and the tip of it started to touch my sisters clit. We then made eye-contact with each-other. We always hated one-another but this time, it seemed like we were happy in each-others company. I decided to take a risk. I went and hugged my sister. It was. . she let me in..." Lesley panted, her motions becoming faster. Her body pumped up and down on me, sheathing me within the body she possessed. She was driving me rapidly toward the edge, and she knew it."Lesley ... it's not safe..." I objected, feeling my body beginning to twitch. I was going to come, and we were having totally unprotected sex. The thought itself was arousing, and for a moment, I wondered that if I came, would I be coming in Trish, or Lesley?"I want this..." Lesley panted,. "I, uh, do. I mean I will," I responded. "It's just a lot to take in, Dad." You'll do fine," he said. "Now, son, I, umm, am going to give you the ultimate responsibility." What's that, Dad?" I asked him as he struggled to find his words."Well, son," he said slowly. "I give you permission to practice on your Mom and sister." Dad!" I fired back. "No! I can't. I can't do that." I'll leave that up to you," he said. "It's just a safe way to learn your powers. I'm not going to mind if it happens.