Since I was very young, I have masturbated by let my bladder get full and then pressing down on it while clamping the muscles so no pee comes out. It feels sooooooooooo good. I can come this way four or five times in a row.

Sometimes, I even do it in public.

Only once did I have an accident. But it was on the back of the school bus and I was the last stop so no one ever knew because I just tied my sweatshirt around my waist.