Son And Daughter

When my son was 15, I suspected he was fooling around with his 12 year old sister. I snuck around and caught them in the act. They were naked, she was on her knees, her ass in the air and he was fucking her like crazy. She was physically very mature for her age with large saggy boobs. I scared them and he pulled out, as he did he exploded cum all over her. I calmed down, calmed them down and asked them about it. They said they had been doing to for almost 2 years. I realized I was super turned on. I got them to promise to stop, at least till I got some condums for them. The next day I presented them wit a box of condums. I figured I wasn't going to stop it from happening, at least I could keep her from getting pregnant by her own brother. That was 20 years ago, although they are both married, they live in the same town and still do it when they get a chance. Me, its given me some super masturbatory fantasies, I always wished I had joined them.