its a quote from the movie scarface which has become poular amoung
people to say when they do things like expose thier penis or
pull out a gun, or a baseball bat, a chainsaw, flip someone off, etc.
it is a way to imitate the persona of tony
montana.
you girlfriend cheated on you and she dont know you know and you pull out a
small sword and say
hello to my little friend before you plunge it into the back of her
skull as you "finish up" doggystyle.