This occurs when sex is had with a woman shortly after her period has ceased. This woman usually has to have a high flow of menstruation for this to happen. The male has sex with the female and it is usually done with the woman on top of the man. Nothing is different from normal sex until the woman has her orgasm. As her vaginal fluid is being thrust out of her vagina, the left over menstruation fluid, the membrane, is also shot out of her vagina. Discovery of the membrane usually does not happen until the woman dismounts the man's penis, but the woman usually knows earlier. The woman's membrane is usually spread out over the man's pubic region. The man is most likely left in disgust. It is appropriate for the man's friends to call him Membrane Man once he shares the story.
Jacob told us the story of his girlfriend's membrane being spread over his pubic area after he had sex with her. We then called him Membrane Man for a great deal of time.