pregnancy, diseases ...
i think masterbation is safest bet.
SEX may help middle-aged men reach old age by reducing the risks of heart disease and other illnesses, according to findings from Bristol University.
A study divided 918 middle-aged men into groups of high sexual activity (those who said they had an orgasm more than twice a week), intermediate and low (less than once a month). After analysing death rates in the study group ten years later, the researchers found the risk of death in the high-activity group was only half that of the low-activity group. This was more marked in relation to heart disease.

