Condom teat, computer artwork. This area, at the end of a condom, is designed to to contain the ejaculatory fluids and to reduce the chances of the condom bursting. A condom is a latex rubber sheath that is rolled over the erect penis before sexual intercourse. It is a barrier contraceptive that prevents sperm cells in the male ejaculate from entering the female reproductive tract. This prevents unplanned pregnancies, and also helps to prevent the spread of STDs (sexually transmitted diseases).