The Big One - S3-E16
Continuity mistake: When Lorelai sits down on the porch swing at Suki's house to talk, they are both sitting right next to each other, sharing the same blanket. During their conversation, when the shots face each of them individually, you can see there is an empty space beside them on the swing, with both sides of the swing's chains visible. (00:20:50)
The Big One - S3-E16
Continuity mistake: In 1.06 - "Rory's Birthday Parties" Paris says "Ten generations of Gellers have gone to Harvard". In this episode Paris says "Five generations of Gellers have gotten into Harvard"
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.