JUST ABOUT EVERY MAN who can masturbate does -- and why not? Solo sex feels good, relieves stress, and is a terrific sleep aid. But here are a few things you may not know about masturbation. It is safe -- but not entirely safe. Frequent or overly vigorous masturbation can irritate the skin, cause a penis fracture, or develop retarded ejaculation. While solo sex teaches men about their own sexual response and helps them avoid premature ejaculation-- some men become so obsessed with masturbation that they lose interest in having sex with their partner. Plus, it may affect the risk for prostate cancer. Learn more.

