The stink mustache is the result of a dirty sanchez, manual sanchez or any other form of shit-to-upper-lip application. It is the actual smell carried around just under the nose until some way can be found to clean it off.
Hey man, what's the matter?
That bastard just manual sanchezed me and now I have this Stink Mustache I can't get rid of!
The Manual Sanchez is a prank created with the computer geek in mind. It consists of coming up behind someone concentrating on the screen, scratching your own butt crack and wiping it on his/her upper lip hence creating a stink mustache that he will have to carry around for a while. Usually reserved for the closest friends or the worst enemies.
I just wiped my shitty finger under Ramy's nose...we'll call this one the Manual Sanchez!