This is a commonly-known Fun Fact. Read any baby book, and it will tell you this. Furthermore, it will suggest that, for baby boys, you cover their penis with a spare diaper or a baby washcloth or something so that you don't get hosed down. This is excellent advice.
Fun Fact 2: Baby boys have studied Sun Tzu and Patton to learn techniques to get around spare diapers and baby washcloths.
No one saw fit to mention this Fun Fact in any of the baby books, so I'll just pass it along.