The officiate starts rattling on about "I choo-choo-choo-choose you" and everyone looks around the room to the ones they have chosen. Richard at Emily. Luke at Lorelai. Rory at Logan. Logan to some trampy girl he's brought as his date. In the background, we see Christopher sneaking in late, and we wonder why this damn wedding doesn't have bouncers, because we know he's only there to bust up all the happiness he can get his hands on.
We fade to commercial as Richard and Emily start their vows. It's a classy touch.
Back from the break, the reception dinner is starting. Luke remarks overly much about the flower arrangements, causing Lorelai to ask him to be "a little gayer, please." Everything and everyone is beautiful. Luke is disturbed about the dancing later on, and Lorelai is more disturbed about the number of people in attendance whom she hates. They work out a plan where Luke will run interference for Lorelai when they get into a situation where she might have to introduce him to someone whose name she can't remember.
They look across the room and see Lorelai's Aunt Totsie. Lorelai warns Luke about letting his guard down around the Totsie: "She hugs you, you smell like her for a month."
Rory spies Logan at the party, and so she can effectively stalk him without him noticing, she hides behind a big guy wonderkilling to another guest how the whole "first cousin, second cousin, cousin-once-removed" thing works. It's still hard to understand, but the long explanation gives Rory ample time to make a lot of assumptions about Logan and his date.
As Cousin Marilyn gets "Totsied," Lorelai sees Christopher come in, and takes this exact moment to explain to Luke about how she had to go over and comfort Christopher a few weeks ago with an all-night Tequila Fest. Luke clearly is annoyed, but mostly because she's acting all excuse-y and strange about it. And, oh yeah, because this is the first he's heard of their little party. My favorite part is that she says she's only telling him now because Christopher is there and in case it comes up, she doesn't want Luke to feel shanghaied. "Yeah," Luke snarks. "That would be bad." Chris walks up and things get worse, and she steps all in it gushing about how she and Luke are dating, have been dating for months, and wow, time flies when you're having fun, RIGHT, LUKE?!