Christopher comes downstairs from his room at the inn – where he could have been staying all the time to visit his daughter Rory – and talks to Lorelai, who is still fussing over the wedding preparations. They kiss, and with very little thought involved, go upstairs to have sex. For a wonder, neither of them have been drinking this time!
Yes, Lorelai is happily trotting upstairs to have sex with someone else’s boyfriend, but if this offends you in some way, you can be assured she is going to be punished for it out of all proportion. This is a show that likes to punish people who have sex. Maybe even Christopher gets punished, not that the thought is likely to anguish anyone terribly much.