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 Greg and Jen take Lark on her first airplane trip, their parental skills are upstaged by another couple travelling with their baby. Also, Joan and John attempt to smuggle their dog, Tank, onto the plane; Matt and Colleen miss their flights when they accept travel vouchers for airline credits; and Heather and Tim run into countless obstacles when trying to get to the airport on time.
Matt and Colleen have a disastrous time babysitting Lark while Jen is at work. Also, Sophia is far from pleased when John buys her a butterfly kit for her birthday; Tim and Heather rehash an old fight from the early days of their relationship; and Greg gives Samantha questionable advice about being an entrepreneur for her school project.
Greg becomes frazzled when Lark rebuffs him and only wants to be held by Jen. Also, Heather refuses to get the reading glasses she desperately needs; Colleen introduces Matt to her eccentric father so he can get his blessing for their upcoming nuptials; and when Cousin Mikey goes through a tough breakup, Joan tries to set him up on a date.
Greg stirs up an old family feud when he finds money he accused Matt of stealing from him when they were younger. Also, Joan takes offense when Heather writes off her forgetfulness as "old age"; Colleen confronts a mechanic she believes is sexist; and Tim makes the kids go through an impromptu earthquake drill to see if they could figure out how to get home without money or cell service.
Dinner gets awkward for Jen and Matt when they find themselves alone without Greg and Colleen. Also, Lark accidentally locks out Greg and Jen from the house, prompting Greg to install a complicated home automation system; Heather and Tim try to sneak wine into an ice skating show to get out of paying at the venue; and John and Joan agree to an impromptu wedding after Colleen mentions that she's an ordained minister.
When Tim gets two tickets to the GRAMMY Awards from his rock star patient, Charlie Puth, he brings Samantha to the show to impress her. Also, Matt and Colleen realize how out of control planning a wedding can get when they meet with their offbeat wedding planner, Ned Gawler; John and Joan join Facebook so they can stay connected to the kids; and Heather manically tries to save Sophia's beloved goldfish from dying.
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.
When Greg insists on being Matt's best man at his wedding, Matt is forced to reveal his secret about their plans. Also, Colleen refers Jen to her aggressive bikini waxer in order to get a referral discount; Joan tries to prove to Heather that Sophia is ready for a little independence; and Clementine gets a job at a car rental office, leaving Tyler home alone all day.
When Colleen goes wedding dress shopping with her future in-laws, she must deal with Joan's unfiltered opinions. Also, when Clementine feels she's overstaying her welcome at the Hughes house, she starts being extra nice to Tim who takes it the wrong way; Greg gets frustrated when Jen can't stay awake after a romantic date night; and John and Matt attempt to build a vanity for Sophia after John rips up the directions.
When John decides to try out for "Survivor," Tim gets jealous and attempts to undermine his audition tape. Also, Colleen confesses she can't swim when she and Matt discuss Hawaii as a honeymoon destination; Jen pretends to get hooked on meditation so she can use the time to play cell phone games; and Heather gives Sophia the "sex" talk.
John's plan to encourage Samantha to skip her ballet class and take up boxing with his trainer, Troy, behind her mother Heather's back has unexpected consequences. Also, Jen tries to discreetly seek a second opinion when Tim tells her she needs tonsil surgery; Joan constantly scares Matt by hiding spiders around him; and Greg grows a wiry beard that irritates Jen.
When Joan's creative writing teacher, Professor Sinclair Wilde, praises her work, John assumes it is because he has a crush on her. Also, Tyler and Clementine invite Matt and Colleen over for an awkward dinner party; Jen tries to hide it from Greg when Lark takes her first steps while he's away on a business trip; and Colleen, Heather and Jen take Dougie out for ladies night when she realizes she might be gay.
When Colleen teaches Matt her frugal ways, he gets hooked when he realizes how much saving money turns her on. Also, Tim attempts to fire Heather from her receptionist position at his office, John tries to break Sophia's fear of flying by taking her for a quick flight on a small plane, and Jen plans a quiet affair for Lark's first birthday, until the family takes over the celebration.
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.