A word used to rip on any person who has annoyed you, pissed you off, ect. Technically a barista (from the Italian for "bartender") is a person who is coffee-house employee, but in the vulgar world we live in these days anybody can be called a "shitty barista" for no apparent reason in most cases. This word is from the movie Zack and Miri Make a Porno
Austin asked out the girl that Jared liked
Jared said "Austin, you knew I liked her! Why do you always have to be a shitty barista?