This happened around seventh or eighth grade
I suppose I was around 13 or 14 years old at the time. I had been masturbating actively for a few months since my health teacher Mrs.K described it in great detail so I figured 'Why not.' I was particularly horny this day for no real reason at all but at that age who needs an excuse anyway.
My brother was in the band at his high school and my mom of course was very involved so she was off doing something in the band room while my brother was at practice so I was left by myself in the car. There I was all alone in the parking lot. You can only guess what I did. It was getting to be that time so I figured why not go for it, no one was around and the sun was getting ready to set so I jumped in the backseat pulled out my then six inch cock and went at it for a grand total of six or seven minutes.
Boy was it great. I blew my load in time to see the campus security guard walk by to lock the gates. He turned around gave me a friendly 'Whats up nod' and went on his way. I don't know if he saw be but it sure turned me on to think that someone might have, even if it was a dude.