1)When one of your roomates drinks the last beer
in the fridge, and chugs it in front of you,
laughing diabolically, while (he/she)finishes with a beltch
2)When you are driving and someone pulls out in front of you, causing you to slam on
the brakes and blow the horn, as well as possibly causing you to exert excess energy to raise you third phalange (your middle, or "fuck-you" finger)
In both instances you think "fuck, what an asstard...this dick needs to fuck off," thus making the asstard a "fuck dick"