I was in my bedroom jerking off when my sister just popped in. She saw everything I was doing and stared at my huge erect cock. " What are you doing!?"she screamed. "Shhh!" I replied. We were home alone but i didn't want neighbors to hear. "Come here" I instructed to her. She came over to my bed. I told her to grab it as I was and to stroke it up and down. She did. As she was following instructions, I started to finger her tight young pussy. She moaned and I could tell was enjoying it. After a few minutes I pulled her on to my bed and got on top of her. I spread her legs apart and positioned my hard cock against her tight opening. With one quick thrust I was inside of her