There was an adult bookstore/movie arcade close to my uni campus that I frequented while in school. The arcade in the back had glory holes and at first I was very self-conscious if I knew someone was on the other side the hole watching me (I would turn my back to the wall). However, later something inside me clicked and started liking the idea of being watched. I started facing the hole and rubbing my hand over my bulge before taking it out and jerking off for them. Eventually I started letting them do other stuff, of course. It was all so new and very arousing back then.