When a male enters puberty, a small thin layer of peach fuzz may grow on the upper lip. Some choose to not look like a dick head, and shave it off. Some choose to remain looking like a dick head, and keep that little bit of hair growing until it becomes condensed enough to be visible.
Many times dickstaches are found on Mexicans, Wiggers, and Blacks.
"Yo dude you wanna hang out tonight?"- Stacher
"Fuck you, you have a dickstache"-Me