Alison is Will's cousin from Los Angeles.
Will and Karen's book is called "The Marriage of Equals" by Rita Pigeon.
Jack: (About Will) He doesn't respect me.
Karen: Ooh, I've got a nice idea. Why don't we be cold and bitchy to him? You know, like I was to the losers on the playground when I was a kid ... and yesterday at Olivia's kick ball game.
Karen: I did not understand the part where Diane blacked out in the middle of an argument, and woke up spooning her maid.
Will: What? (Realizes) She didn't, you did.
Karen: Yeah, that makes more sense.
Will: Slow down there, Augustus Gloop. You don't want to get sucked up into the pipe.
Will's crack to Grace as she is testing each of the wedding cake samples refers to the winner of the first Golden Ticket in the movie Willy Wonka & the Chocolate Factory. In the movie, the boy was shown to have a voracious appetite. He eventually fell into the chocolate river and was sucked up through the filtration pipes to the fudge room.
Jack: We're gonna go to Bea Arthur's one-woman show and yell out "Maude!"
Bea Arthur played the title role in the 70s sitcom Maude.
Will: Just give me a signature. The sooner you get that over with, the sooner you two Heathers can get back to your Heathering.
Jack and Karen had been whispering derogatory remarks about Will to each other. Will's response is a reference to the 1989 film Heathers, in which three high school girls (all named Heather) insult other, less popular girls.