Mace wants to downplay Philip and Simon's sexual orientation on the wedding invitations; Liz tries to convince Bobby's priest (Tom Bosley) that they are ready for marriage.
After Liz and Bobby adopt a stray dog, everyone begins to question one another's parenting styles.
When Philip cracks up in the china section of a department store, a TV psychiatrist (Andy Richter) steps in to help him through his crisis.
Mace is disinclined to go camping with Philip and Simon; someone shows a talent for pole dancing at Liz's bachelorette party.
On Oscar night, Mace and Philip land in the emergency room where their nurse (Louise Fletcher) has a less-than-winning personality; Audrey displays a talent for ridiculing celebrities on the red carpet.
Bobby gets cold feet when the wedding plans accelerate; Philip discovers Mace is related to a famous playwright.
The O'Neils discover that Simon used to perform with a boy band in the 1980s.
Mace goes on a fishing trip with a longtime buddy, but the two men have old scores to settle; Maddy becomes infatuated with Simon's teaching assistant.
Simon asks Audrey to make costumes for a musical production that promotes gun control, but Mace blows his top when he finds out.
Mace poses as a couch potato in a display at Philip's gallery; Audrey and Simon become buddies while concocting the perfect sauce.
Bobby finds out Liz has discussed their sex life with her dads.
Bobby's and Liz's families try their best to blend very different styles of celebrating Christmas; Bobby feels pressure to compete with Philip and Simon's gifts for Liz.
Audrey arrives with an unusual abstract painting that everyone agrees is awful; while Audrey is away, Mace sells her painting to Philip.
Mace lies to his mother (Olympia Dukakis) about Philip and Simon; Philip tells his stuffy designer that Liz's future in-laws are wealthy and influential.
Liz and Bobby flee to Vermont after their families refuse to work together while planning an engagement party.
When a dead swan threatens to land a political candidate in hot water, Philip and Mace try to help resolve the situation.
While the O'Neils attend a wake, Simon and Philip introduce karaoke to the patrons at the family's pub.
Mace learns a lesson about stereotypes from his gay doctor; Philip's party planner (Victor Garber) makes a startling confession; Philip and Simon throw a Halloween party.
Bobby convinces Philip and Simon to invite Mace to a Red Sox game; Liz tags along with the O'Neil women to a basement sale.
A pipe bursts while Bobby is making coffee in his future in-laws' kitchen, and he calls his father to fix it before anyone gets home.
Liz challenges Bobby to contact his ex-girlfriends and tell them why he broke up with them.
Bobby and Liz cope with parents from wildly different backgrounds; the couple break the news to their families of their secret engagement.