Swim team speedo sharing!

In jr high I was already really into sexy tight underwear for men. I joined the swim team because I was good at swimming and it gave me an excuse to walk around in a tight speedo in public. I wore my speedo all the time! However, one day I got to practice after school and couldn't find my speedo in my backpack! I told the coach and he went to the office and got me a loaner one. I changed into it and I couldn't help but get hard almost instantly! I had to hide it so I jumped right in the pool. After practice we all showered in our speedos and I took my time. I waited until everyone else left and then I started to rub my bulge in the loaner speedo. It was a size small and fit me perfectly! My smooth bulge was sooo tight in the hot wet speedo. I kept rubbing it and couldn't stop thinking about how good it felt. My eyes were closed. I was imagining so many things! All of the bulges my teammates had, my coaches bulge in his speedo, and all the bulges I've ever seen. Right then I lost control and my hung cock shot my load right into the speedo! I turned around and opened my eyes and saw my coach standing between the lockers watching me.... he told he was just going to remind me to make sure I put the loaner speedo back in his office after my shower. He never said anything about watching me. I didn't know how long he was there for since I had my eyes closed...but I did see he had a big bulge in his shorts.