Gradually I grew bolder and did some exhibtionism standing in our huge picture window, even venturing out into the back garden. Sometimes I,d put up m... two man pup tent, then take off my clothes, walk around for a while before returning to jerk off and then put my clothes back on. One day I pushed my luck too far as my step sister who usually lived with her grand parents was staying with us and had been out doing some shopping suddenly came back unexpectedly. At twenty she had already had boy. I figured in all the running around I missed her so I went back to the room and still no sign but at least it had quieted down next door. I called my wife's cell and that when I nearly passed out. I could faintly hear the distinctive ringtone on her phone that rings when I call coming from the room next door. I stood frozen in a mix of silence and a muffled party next door trying to hear it for sure then voice mail. I couldn't leave a message. I just hung up. I called back but this time. “I’m so sorry. If you don’t mind me asking, why do you stay with him?” I asked. “I don’t know. I guess I just don’t have the guts to leave him. We’ve been together since we were sixteen,” she said in a sad voice. A minute later, we pulled into our driveway. “Okay, we’re home,” I said as I parked the car. “Want to come inside for some coffee or something?” I asked. “I don’t like coffee, but I’ll come inside,” she replied. 'Perfect, she’s letting down her defenses!' I thought to myself as Amber. Her body was still now although I still hadn't come myself."Thank you daddy," she sighed."Thank you Clare for all your hard work," I replied. "Now call Carol in she can sleep with me tonight." Yes daddy," she said meekly."Can I ride you granddad?" Carol yelped."Sure," I agreed.Quickly she shed her few clothes and then she jumped astride me and my hard cock slipped deep inside her."Oh yeah," she shouted, "ride 'em cowgirl."I watched as her young body bounced and writhed on top of me until I.