Haven't seen too many stories about first-time experiences...My early days are a constant source of fodder for even my present activity!
My 'love affair' with masturbation started when I was a sophomore in high school. My English teacher was a woman in her late thirties who was the mother of a girl I knew in another class. This girl and I knew each other from elementary school and were pretty good acquaintances although not good friends. One afternoon we were walking home together and she suddenly blurted out that her mother was in the habit of taking a shower every afternoon when she came home from school. She said if I would agree to let her watch me masturbate, she would let me come to her house and see her mother showering through a vent you could access through the attic. Naturally, I was turned on by even the thought of this. My teacher was an attractive, full-bodied woman with strong arms and legs that all the guys used to kid about. We used to talk constantly about her breasts, her legs, what color her cunt hair must be, and the things we would do to her if we had her naked, tied up, and blindfolded in a clubhouse. Now, suddenly, here was a chance to actually see her naked and all I had to do was to let her daughter watch me jerk off. This was truly a no-brainer! That afternoon we crawled up into the attic space and her daughter rearranged some insulation and there, in pretty plain view, through the sides of the vent, you could see the bathroom and the shower. My heart started beating and I started getting hot as I fantasized what I was going to see. At one point, while we were waiting, Cheryl said 'Come on, take off your pants and let me see your cock.' I did and let her take a good look at my very strong erection. I let her touch it and it felt like I was getting even bigger.
After what seemed like an hour but must have been about ten minutes, her mother came into the bathroom with a large towel around her. She turned on the shower and then got out of the towel. From my vantage point, sitting cross-legged with my head peering through the slot, I could see everything! Her mother was amazing. She had huge breasts and a jet-black, full bush. I started masturbating as I looked at her and Cheryl started playing with my balls as I stroked myself. Once my teacher started soaping herself up, lathering her breasts and bush, and working her both hands up and down her legs, that did it for me: I shot my load, much of it on Cheryl's hand. I remember saying 'I really would like to fuck your mother.' 'Well, that's not gonna happen,' she said, but she knew I just said it to hear how it would sound.
You can bet I never looked at my teacher again the same way and spent many, many nights wondering what she would have done if I had told her (which I fantasized constantly about doing) what I had seen!