It doesn't have to be testicle related to make me fear pain (i.e. I am afraid of being clubbed in the head by a flashlight) but the idea of a woman causing the pain and focusing it on my testicles is what is sexually addictive to me. No- I don't get the same effect from penis pain or even from the skin pain associated with cutting, burning or whipping the scrotum. Those things just hurt. Testicle pain hurts like a mutha but gets me a hell of an erection on the way!