It is a slang used among porteño´s spanish speakers. Literally, it means Suck on my dick. A better translation could be " Blow me ". Mostly it is used when you refuse to do something and you are angry even for being asked to do it. The same expression has many other synonyms such as: "chupala" (Suck on it), "por que no me la chupas?" ( Why don't you suck on it?) etc. Generally, all of them with a similar meaning.
1- ¿ No me traes los cigarrillos?

Chupame la pija. Levanta el culo y traetelos vos.

Would you bring me my cigarettes?

Blow me, get up your ass and go get them yourself.
by The mesias September 28, 2009
Get the Chupame la pija. mug.