It didn't seem like either of us were going to surrender this oral battle. It just got more and more intense the longer we went, until finally I said,..."I've got to cum soon." There was no way she was going to let me off that easy. She jumped up, spun around, and said, "Don't you dare," as she lower herself down, guiding my saliva-soaked cock towards her wet cunt. When she had eased it in half way she took her hand off my cock to let gravity do the rest. In a couple of seconds I was balls deep. Mark could not help but see Dana’s wedding ring glitter against the backdrop of her petite hands clenching Keith’s muscular ass. He also was aware that Dana and Keith were again kissing open-mouthed and deeply as Keith’s cock filled Dana. After a few minutes, Keith arched his back and his hands grasped Dana’s big tits as he continued to pump in and out of her sopping wet pussy. The squishing sounds of their lovemaking filled the room. Dana was mesmerized by the look on Keith’s face as he fucked. Opening the door, I stepped out and my sister's first words were, "Oh my GOD!" as she looked me up and down. Thankfully, I did have the towel around my waist so I was not naked as I usually was in my old apartment. If I did not know better, I would have sworn my sister was checking me out. That was just weird.Before I could say anything sister number two, came out of the room they shared. She was not subtle at all as she openly gawked at me, adding, "Looking good there Brian."I retreated to my. I had had sexual thoughts about my Mom for a few years but never acted on them. I had glimpsed her many times either coming out of the shower or getting changed in the bedroom when she had forgotten to close her door properly. The last time I saw her she was standing in her bedroom getting ready to go out to dinner with some clients. She was wearing a dark blue bra with lace along the top, matching panties that were high cut in the legs and she had on stockings with a garter belt, and wore.