I just read the post about a guy doing it in the library. I reminded me of what I used to do in high school, and got me aroused at the memory.
When I was a freshman in high school, we had one period called study hall, when we were supposed to do as much of our homework as we could, prepare for tests, etc. We had a choice of going to the cafeteria or the library. I chose the library because the cafeteria was always too noisy to concentrate.
I liked to have privacy, and found that there were a couple of desks squirreled away back in the stacks where I could study in peace. One in particular was neat, because view of it was blocked from every direction but to the right, down the walkway between the book stacks. I could sit there and easily see if anyone was heading my way from quite a distance.
Sitting there one day, I was, for some reason, kinda horny, and popped a boner in my pants. I massaged it some, and wanted to masturbate, but it was too complicated to get my penis free of my briefs, and I didn't want to mess myself. So I got up and walked around a bit, and in the process found a section of health books that had anatomy and things, so I took them back to my little hideaway. Well, that didn't help matters any. I got even more horny, and had to do it. I struggled to get my penis out the fly of my briefs, and jacked off sitting right there at the desk. It was really exciting, since there was danger of someone coming, and I had a great orgasm, spattering my semen all over the inside of the desk. Wow, that was a rush.
The next day I thought about it in advance, and on the way to the library, I stopped in the boys room and removed my underwear, stuffing them to the bottom of my book bag. When I sat at 'my' desk, it felt really neat, and I knew I was in for some fun. I went back to the books, and found one that talked about sex, and it had a large section on masturbation. I rushed it back to my desk, and read it carefully. It was several pages long, talked about how most boys do it and many girls do too, talked about different ways they did it, etc. The most I'd ever seen in print about masturbation was the definition in the Boy Scout Handbook, which only said, 'Sexual self abuse.' Really helpful, eh? Made it sound like I was mutilating myself. I'd been masturbating since I was a very small child, so I knew it didn't hurt me, but that didn't lessen my fascination for the subject. Just the word 'masturbation' would give me a boner. So of course I jacked off again under the desk. If someone came in my direction, they wouldn't be able to see, but I could stop and stuff myself back in my pants if necessary before they got close.
Over the next couple of weeks, I found several anthropology books that described customs in undeveloped cultures, and I read about cultures where children went naked all the time, and where masturbation was openly practiced among children. There was even mention of mothers masturbating their infants as a way to calm them down when upset. All this of course led to many opportunities for orgasmic pleasure, and my little hideaway became a wonderful refuge for pleasure in the middle of the day.
I used that desk all four years of high school, and found a similar situation in college. I was nearly caught several times, but was very good at hiding what I was doing. Years later I went back to the library at my old high school, and that same desk was still there. I got on my hands and knees and looked underneath, and sure enough, there were my old semen stains all over the inside. But what was even more interesting was that I saw newer stains, and some were still fresh. I touched one, and it was still sticky. So I wasn't the only one who discovered how fun that desk could be!