Friday Night's Alright for Fighting - S6-E13
Continuity mistake: When Richard hands Rory her martini, she puts it on the table in front of her. In the next shot she puts it down once more.
Friday Night's Alright for Fighting - S6-E13
Continuity mistake: Lorelei is eating marshmallows covered in chocolate syrup. The amount of marshmallows on the plate changes as does the chocolate to marshmallow ratio in the bag next to her.
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.