Incident with Sis

It was around 3 years ago, I was deeply into incest. I used to spoon my sis when she was sleeping. I also used to wear pants without underwear so she could see it. It was going smooth for a time. We used to hug, cuddle and sleep together but nothing had been done. One day, when we were on bed, she slowly started raising her leg and placed it on top of my dick. I had no underwear and was hard. She slowly played with my dick with her leg for about 30 min. My mom was also in our room at that time so i couldnt do anything. We were inside a blanket and she was clearly teasing me. After that, she went to her room and i jerked off heavily. We never talked about that incident but to be honest, i still jerk today remembering that day. Do you guys know how can i revive it again?