douche a twelve

Screwing something up right at the last second when everything seems in hand; choking at the worst possible time in the worst possible way. This stems from the ambulance mission in the video game GTA III, which has twelve levels and takes forever and is hard and random and makes you want to throw things when a person you are trying to rescue on level 12 spawns inside a sidewalk and cannot move or runs into your ambulance and kills himself causing you to fail the mission and lose all that time and have to start over. Douching a twelve means to fail the mission on the final level, which, trust me, is just the worst.