Penis problems 13 years old

Precum will not hurt you, it's a natural lubricant, and is typical emitted when a male is highly aroused.

There is some discussion over whether precum fluid can contain active sperm or not.  If the male has ejaculated recently, it is thought that there is possible still an active sperm in the urethrea (tube inside the penis that cares the urine or the ejacuation out).

To be safe, use a condom to keep any precum out of a woman's reproductive tract unless she is on some other form of birth control, like the pill or a spermacide already in place.

If you are manually stimulating him, make certain that you don't transfer anything that comes out of his penis (precum or ejaculate) to the woman's genitals.  We don't want you to risk pregnancy.

Hope this has helped.