Recently started having a slight dull pain in my left testicle while masturbating. If I stop, or I finish, the pain goes away completely. Only during masturbation does it feel this way, and it isn't enough pain to inhibit my ability to do it, only enough to make me notice. I've been using a fleshlight for awhile now, so one of my first thought was that I might have gotten an infection due to not cleaning it enough. Or maybe I've been masturbating too much recently. Regardless, does anyone know what the likely possibilities are, and how to fix this issue?