Back home, Mike and his mother were fucking for a second time that evening. After the previous, early evening session, Mike had done his weekend homew...rk to leave himself free for the next couple of days, whilst Claire had packed for the weekend before watching TV. She needed to be up early the next day, so they got to bed by eleven.Claire lay on her stomach, Mike lying flat on top of her. They nearly always fucked on top of the covers with the light on, but for once, they'd got into position. Loud enough for her to hear. I had removed my pant and my boxer and i knew she would come. I started masturbating and waited for her to come. When she came i started to enjoy the masturbation. She was standing at the door of the bedroom looking at me masturbating near the door of another room.She watched me for another 5 minutes, her mouth open. Then I saw her and acted surprised and she ran back. I went into the bedroom. She was sitting there watching the TV. I went and sat next to her. She. "Ten?"Shake."How about five?"A pause, and then a nod. Great ... five times. Not as many as I was hoping for, but I can work with that."So after five times, you're pretty comfortable with me jerking off in front of you?" Yes ... I suppose so." Would," I asked, already knowing the answer, "it be weird if I just jerked off in front of you without needing your advice?" Yes. Yes, that would be weird." Okay."I took a deep breath. I'd spent a few hours thinking about little hints that my sister had. I also became aware that several of the boys had noticed my high beams and were giggling nervously. I glanced at Matt, but the way he turned and the expression on his face left me uncertain if he saw, but there was just enough of a smile on his face that my juices were starting to flow. I excused myself to the restroom. Once inside, I went to one of the stall and pulled down my shorts and panties. The panties were soaked, but I didn't care about that right now. I slid my finger into my slit.