I'm a Kayak, Hear Me Roar - S7-E15
Continuity mistake: When Lorelai picks up Rory and they head off on a drive there is no rearview mirror on the Jeep's windshield, but when they run out of gas and start their walk, a rearview mirror suddenly appears.
Chosen answer: Lorelai and Christopher get married impulsively in Paris but they get divorced shortly after returning home. I don't know the exact number of days or weeks but they definitely weren't married for more than a couple of months.