Those Lazy-Hazy-Crazy Days - S3-E1
Continuity mistake: In the first shot you can see Rory's laptop open in the background, but when she walks over to her desk and sits down, it's closed. (00:02:15 - 00:04:45)
Those Lazy-Hazy-Crazy Days - S3-E1
Continuity mistake: After Luke and "Mimi" talk at the diner Lorelai comes home, and while she and Rory sit on the couch note the open window behind them, with a clown pillow in front of it and the porch chair on the other side, but when Lorelai asks for her purse because she's hungry it cuts to the exterior shot, and nothing is blocking the view through that window. (00:41:00 - 00:43:00)
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.