As usual, I had only come in my boxers, and they had come off for masturbation. I sported a semi-erection. She pulled me up from my crouching position... and, smiling, took me by the hand.-Come with me young man. Don't worry, she won't tell anyone anything. I followed Nana towards the water, somewhat embarrassed of my nudity.In the middle of the pool, nearly waist-deep in the water, was a young woman, probably about my age or a couple years younger. She was dark skinned, and had clearly performed. Her mothers head was moving up and down as her mouth deep throated his shaft.Closing her eyes and taking a deep breath, Meg reluctanly spread her legs and slowly started to finger her pussy while Frank stood getting the entire scene of the three of them on film."Rub your sweet young pussy for the camera Meg," Frank ordered. "Show me how much you like watching your Daddy getting his cock sucked by Mummy."Meg found it hard to do this in front of others, especially having to do it in front of her. I peak around the furnace that is in the center of the basement. I peak around to see my sister, her legs spread. My eyes were immediately drawn to her tight pink pussy, her large labia swang ever so slightly as he was rubbing her clit back and forth. My eyes followed up her smooth stomach to her still perky breasts. My penis had already begun to grow. I looked up a little further and noticed that my sister was sucking on the head of an unbelievably large black dildo. It was 10 inches at least.. It was as hard as it looked! As soon as I sucked on it, Jess began moaning loudly, not moaning like it was something that just felt good, but moaning like she was already on her way to an orgasm! I decided to test that theory, and began lightly nibbling her rock hard nipple. She gasped! I ran my tongue in circles around the nipple, flicking it every now and then, and returned to nibbling it. I repeated this process over and over again, occasionally switching nipples, but always playing with one.