I am really beat, I am going to shower and climb into bed. Do you need anything?” she asked.“No, I am fine. You go ahead and I will see you in the...morning” I replied.I heard her start the water running for her shower and heard her close the bathroom door. I then went down stairs and fixed myself a quick bite to eat. Not really very hungry but needed to kill some time. About an hour later Melissa had gone to bed and the house was quiet, I went back to the office and sat at my desk and started to. Cara had closed her eyes and was startled by her sister’s hands on her stomach. She looked down and saw why her sister was moving her and said, “Oh, Aaron, I’m so sorry!”I mumbled into her vagina, “It’s OK”, which caused Heather to laugh. She reached over and spread her sisters pussy apart, just as Cara had done for her. I went back to work and, like Heather, I soon was able to home in on Cara’s clit.The feeling seemed to go through her like an electric jolt. Up and down I went over her clit. Suddenly a flash appeared and it seemed to light up my whole room I was dazzled by the brightness and couldn't see so I turned over and buried my face in the pillow while behind my eyes I could still see the flash I waited for my sight to return and while I was waiting I started to have a funny feeling like I wasn't alone so I went to turn over and found that I couldn't "what the hell!" I thought am I dead maybe the lightning struck me maybe it shorted something out in my brain or something and. Her shy submissive behavior turned me on even more and I had to fight to control the hard-on that was growing in my pants.I was working so, I knew I was taking a real chance, but I couldn’t help myself. I slide in behind her and I had to will myself from pushing my cock into her big delicious ass.I again leaned close to her ear and whispered, “Why are you standing over her away from everyone?” Her head dropped again and she said she was just watching her son play. At this point my cock was.