It's a word used as a reply to someone who gives you an answer that you wish was different. Specifically, when you pose a suggestion and the other person can't/won't cooperate with you.
It's a way to say "you suck but I still love you" in a less homosexual tone.
Bret: Do you want to go see a movie or something?
Nathan: Nah, I've got to finish my Spanish project.
(under his breath)
I love playing footsies in the dark with you...