Five years later, Paul and Ally are on the verge of splitting; Jim and Jackie are in turmoil; Luke and his girlfriend, Maya, drop a bombshell at Christmas dinner that will change everyone's lives forever.

The reality of Luke's announcement hits; Paul and Ally worry about the decision he and Maya made and whether they should support them; as a new year starts, the family gather together with Maya's family, united in their love and worry.

Ally is appalled that she's about to turn 50 and bans the family from ever mentioning that number; Paul tries to help Luke, who is overwhelmed by learning to drive and become a dad; Ava meets a charismatic girl called Holly.

Paul and Ally find themselves parenting Jim and Jackie as well as Luke. Ava and Holly get closer and Ava decides to take a risk, while Paul meets an old friend and realizes that he might, after all, be happy.

Paul and Ally take a "family" vacation without the kids. Luke makes a decision about the future of his education and life with Maya.

Paul and Ally are on their way back from their holiday, Luke and Maya discuss Luke's future prospects when Maya's water breaks and goes into labor. Ally argues with Maya's mom over ignoring Luke's role during Maya's labor reiterating she's fighting Luke's corner. Luke has major anxiety, Maya's father asks him to step up and be a man in a very loving and polite way. Paul interjects after finding Luke, then Luke talks to Paul about his father-in-law Sunil's request and Paul explains to Luke that anybody can be a child when anxiety comes and he says he'll teach him how to be a man. Later they are seen in the nursery where Paul teaches Luke how to bottle feed baby Jay where the maternity ward's nurse says to Luke he's doing amazing. Maya asks Luke to stay the night instead of her mom, Ava saves the day by bringing Jay's newborn hat which triggered part of Luke's anxiety after not finding it for Maya's labor. Everyone walks out to have breakfast as Maya's dad paints a beautiful picture of the breakfast place dishes. Paul and Ava are both on their phones. Paul says congrats to his father on becoming a great-grand dad, while Ava talks to Grace on the phone. Fade out.

As Paul and Ally try to help Luke, struggling with being both a dad and a student, they find they have very different ideas about the best way forward. Jackie's condition is becoming more noticeable, and Jim is determined to help out.

Jackie's health is continuing to worsen. Paul helps out a distressed Luke but finds himself in more conflict with Ally. At Baby Jay's naming party, Ava declares her love, and Paul makes an offer that will take him and Ally back in time.