True story. I hope you enjoy it.
When I was 15 or so, I used to get very turned on by a teacher in school, Miss Stewart (not her real name) was a short curvy woman with short dark hair who had great legs. Often in her class I'd get an erection and be sitting there looking at her tits or arse and getting my teenage cock rock hard.
One day I was moved to a seat in the corner of the room with no-one sitting next to me, this desk was slightly behind all the others too, so none of the other pupils could actually see me unless they turned right round in their chairs.
One day, sitting there listening to the teacher and with my cock all stiff, I started to rub it through my trousers. As I say, the advantage of my seat was that I could watch everyone in the class, but they had to turn round to see me, also, by leaning forward slightly, the edge of the desk covered me enough that Miss Stewart wouldn't see my hand on my genitals, so I took advantage of this by slowly rubbing at my hard cock-end throughout the lessons, sometimes even when the teacher was looking at the class and speaking.
I usualy ejaculated in my pants near the end of the lesson and could feel the warm wetness as I left the classroom smiling at Miss Stewart.
After a few weeks of this without being caught, I decided to go a step further. I wore a longer jacket to school that I didn't take off in class, and when Miss Stewart turned her back, I quietly unzipped my trousers and pulled out my hard penis, being careful to watch out for anyone who might be about to look round and pulling my jacket over my lap so that they wouldn't see anything anyway.
Wanking the whole length of my cock was different from just rubbing the head of it through my trousers, so I mostly stroked while Miss Stewart had her back turned at the blackboard, and after 10 minutes or so of furtive pumping, I came.
The teacher Miss Stewart stood at the front of the classroom facing the blackboard and reading aloud from it whilst I ejaculated huge amounts of hot sperm while looking at her tight bum and shapely legs clad in see-through black tights, or sometimes glancing around the room at some of my female classmates.
After orgasming, I put my cock away, spunk rubbing off onto my pants, and with some cum on the inside lining of my jacket too.
I managed to do this a few times, always enjoying a powerful orgasm, although I sometimes had to bite my lip to stop me from making a sound!
Thinking of it now, I'm amazed at my own cheek , and that I managed to get away with it without being caught. But I'm also hugely turned on by it too!
I wonder what all he other boys and girls in my class would have thought if they knew that while they were concentrating on their work, I was only a few metres away, shooting sticky cum from my cock. I hope it would turn them on.