Colleen joins John and his Air Force buddies for his annual tradition of dirty Christmas caroling. Also, Joan tries to hijack Lark’s first Christmas from Jen and Greg, Samantha sneaks out with her friends and is caught when a photo of her and a mall Santa is posted online, and Tyler announces his plans for college,

Greg feels threatened by Jen's handsome assistant; Tim and Heather plan a prank.

When Tim accidentally shaves off a huge chunk of eyebrow before an important photoshoot, he hopes Jen and Colleen's grooming expertise can fix it. Also, when Gigi passes away, Greg makes an anonymous donation with the money she left him, but later realizes he wants to be recognized for it; John learns firsthand what Gigi's life was like at the nursing home; and Joan honors her mother's memory with unusual jewelry.

When Greg and Jen hire Allie, a private chef, to cook for them on Valentine's Day, the evening isn't as romantic as they had hoped. Also, Matt and Colleen try to adopt a dog from Ruth, a judgmental animal advocate; John and Joan attempt to buy a classic car from dealership owner Gavin; and Sophia gets a necklace from a boy for Valentine's Day, to the chagrin of Heather and Tim.

In the season finale, when Colleen and Matt miss all the flights to Mexico for their wedding, they question if they will ever get married. Also, Greg and Jen get into trouble when they share a cookie with a fellow plane passenger who has a severe allergic reaction to it, Joan and John rush their dog to the vet after he swallows Matt's wedding ring, and the Hughes family moves into Tyler and Clementine's tiny house when a fire breaksout in their kitchen.

When Heather finds a map to a time capsule she buried with her brothers as kids, they all set out to find it and dig it up. Also, Jen learns she has a low car service rating so she books rides across the city to charm drivers and increase her score; Joan joins her neighbor's poker game in an effort to win an unusual prize; and John finally gets hearing aids but they aren't having the effect he was hoping for.

Jen and Greg decide to take turns dealing with her annoying parents when they come to visit. Also, when Tim and Heather chaperone Samantha's dance, Heather runs into an old flame; Colleen cashes in the many "love coupons" Matt has given her as gifts over the years; and Sophia digs up disturbing information when she investigates the family lineage.

When Colleen and Matt try to impress a potential birth mother, they have a hard time competing against another rich, swanky couple. Jen’s pregnancy takes a toll on Greg; Heather lets John take credit for her housekeeping while Joan recovers from knee surgery. Tim arranges for Tyler to record a demo at a friend’s studio

When Tim and Heather realize that being grandparents is very far off in the future, they decide to have another baby. Joan gets frustrated when she keeps getting tasked with watching the grandkids. Jen and Greg decide to look for a new house. Matt gets a job offer in Germany, which is problematic for Colleen and Lucas.