Taking the first shot from a sniper rifle with a clean barrel. Extremely difficult, you have to anticipate where the shot will go. only after the first shot you can adjust your dope (Data On Previous Engagement). also after a first shot is fired the inside of the barrel will set on carbon residue that will change the flightpath of the bulet.

The phenomenon of having to come out as bisexual to the same person/people repeatedly because they assumed or hoped that your sexuality was a "phase." Refers less to the holiday and more to the 1993 Bill Murray comedy film in which the main character experiences the same day over and over.