On Christmas Eve, for their first Christmas together, the couple go to Dan's hometown of Bamford in Bristol to meet his family, rather than be with Lisa's parents in Barbados. Upon arriving at the Colman family home, the couple are greeted by Dan's parents Dave and Sue, his siblings Julie and Jake, Julie's husband Trevor and their son Bert. Lisa joins Dan and his family at the local pub "The Bull", where she is told that when he was four, Dan called his penis Keith and wrote to the Queen when a swan bit it, and is also told that Dan once dressed up as Mariah Carey.
On Christmas morning, Lisa and Dan wake up and exchange gifts, with Lisa giving Dan guitar lessons and he giving her a trip to Paris. The two go downstairs where they are given badly knitted Rudolph jumpers by Sue. During Christmas dinner, Lisa learns about Dan's ex-girlfriend Jenny (whom Dan later says that he dated for a month when he was 19). That night, Lisa joins Dan and his family in visiting his uncle Tony and aunt Jade. Whilst Dan is away with Tony, Jade takes Lisa upstairs to has her try on her old wedding dress. Dan is told of what is happening by Sue and attempts to go to Lisa, but is told not to come in as it's bad luck. When coming back downstairs, Lisa sees Dan kissing Jenny (due to Tony spiking his drink with drugs and started hallucinating and thought Jenny was Lisa), which causes an outraged Lisa to slap Dan and leave.
The next day, Lisa has left the house and isn't returning Dan's calls. After failing to get a train back to London, Dan is called by Lisa, who is still upset about what had happened and accuses Dan of cheating on her (despite Dan telling her that Tony spiked his drink) and refuses to allow him to return to their flat, saying she needs time to think. Lisa then appears in two flashbacks Dan has; the first where she and Dan play around with each other in a park and kiss, and the second show her and Dan in a cafe where she playfully dabs coffee frothing on Dan's face.
On New Year's Eve, Dan goes to London and arrives at the flat to reconcile with Lisa, only to find the flat empty. Dan is told by his neighbor Roger that he saw Lisa leaving with a suitcase, making Dan think that she has left for Barbados. Upon returning to Bamford, Dan is chosen to be the volunteer of Bert's magic act. With the use of Bert's "magic", Lisa appears in front of Dan and they kiss, with Dan mouthing "I love you" to Lisa, to which she smiles happily. Later, while sitting in the house's hallway with Dan, Lisa tells him that Sue had driven her (in a flashback, rather badly) from London to Bristol and had told her about Tony and the drugs. Dan points out that he told her that, but Lisa says that she didn't believe him because she saw him kissing Jenny and she was "blonde and perfect". Dan points out to Lisa all the things she has that makes her perfect, before he and Lisa agree to go to Barbados next year. They are then joined by a rather drunk Sue who wishes them a happy new year. Dan tells his mother that she's amazing while Lisa says that she's gert lush. After Sue leaves with Dave, Lisa tells Dan that she loves his family, to which Dan replies that he really loves her.
Lisa is last seen with Dan who says that his New Year's resolution is to spend every moment with Lisa, who jokingly says that she's more interested in Keith, to which Dan replies if he can see "Sandra" (nickname for Lisa's vagina).