Someone who has no other point in life than to make your existance miserable. Usually ends up with a short, ugly girlfriend who cheats on him... only because he cannot do better.
"Rob, why did you go from Erika the hottie to that ugly girl Sammi?"
"I don't know, I couldn't do any better. And she was willing to f*ck before I even asked her out."
"You're a COMPLETE DOUCHEBAG."