some times but not every time after ive masturbated the top layer of skin on the end of my penis seems to crack, go white and peal. When its hard the skin on the end seems very tight and smooth not skin like texture more like shiny rubbery plastic ive been checked out at the doctors and he gave me the all clear and said it looks normal which it does on the slack its just after ive masturbated really! any ideas? i dont do it often or for that long or hard really :s