Kate said that she was repulsed by what she saw and had wanted no part of that kind of sick sex.Philip told us that they had given up thinking of swin...ing and had been looking for just another couple to have sex with. They had been turned off by large groups.I asked point blank if they were positive they were clean of any disease.Philip told us that both Kate and he had just recently had physicals, they had been tested for Aids and all other S.T.Ds. It was a compulsory thing for all federal. She said they had been separated in the last few weeks, and would love someone else to be in her giant empty house with her. Then it clicked in my dumb brain what was happening (remember that thing about me being really slow to see these signs?).Then I got nervous. If Sarah were to end up going down on me, would she be able to tell I was very recently with another women? Maybe she didn't even want sex at all! Maybe she just wanted to feel safe with someone who's never made a move on her. Was my. " But sissy, why?" I wrapped her in a hug."I can't tell you. I just want you to know that I love you. You're the best little sister ever. And I’m sorry I yelled out you earlier." It's ok. I love you too sissy." I pulled away and gave her a kiss on the cheek."Be a good girl." I tucked her back in under the covers and within seconds, she was fast asleep.I headed out of her room and down to my mom's. I didn't want to wake her. She had fallen asleep to some movie on TV. I could tell she had been. Small round tits that you could see thru the outline of her tees and tank tops that summer. But the one thing that turned my head with her was her ass, it was perfect in every way, not too big, not too small but in jeans or shorts it was a wonder to behold.After several months of working with her Dad we became very friendly but in a very innocent way, as nice as her ass was she was just a cute k** to me. Toward the end of summer she told me she was starting community college about a mile from.