penis head

ive recently noticed that after an erection during masturbation or sex, that when my penis becomes flacid again that the head of my penis wrinkles, now ive never seen this happen before. A day or two after the sexual encounter the skin from the head of my penis sort of peeled off, not like a layer of skin, but when rubbed during washing that a thin layer of skin would rub off. I assumed that after the erection when the head went wrinly that it could be new loose skin formed because of it. I have no idea what it is and i was wondering if anybody could give a heads up and any information as to what it could be.