I was seventeen and had a couple of girlfriends and got involved in heavy petting but did not have any knowledge of masturbation in any form.
I came from a very strict family where sex was not talked about. My girlfriend and I were heavily petting in my mini one night when she suddenly pulled my cock out of my pants without warning. I did not know what was going on but the feeling was tremendous. I told her to move her hand up and down my throbbing cock even though it was new territory for me. She obliged and while she didn't know what to expect as well she carried on. Of course, in no time I had this feeling I had never experienced before and I shot all over her, the roof of the mini and me-it was fantastic. Of course, we progressed from there but that is another story!