Gaby has a nightmare about being iced out at Kevin and Katie’s wedding but is woken by Katie bringing coffee—and snapping unflattering photos of her. Katie urges her to get ready for their plans.
As Gaby self-tapes a cooking show audition, Katie and Kevin interrupt. Meanwhile, Manny complains about their noisy neighbors, and Gaby agrees their behavior is disrespectful—especially since they could be future in-laws.
Katie treats everyone to breakfast burritos. Kevin reveals that Katie signed them up as Santa and Mrs. Claus for the holiday stroll. Gaby questions their relationship, reminding him how mean Katie was to her growing up. Kevin defends her and asks Gaby to give her a chance. She reluctantly agrees.
Gaby, feeling tense, confronts Katie about her past treatment. Katie doesn’t recall it the same way and insists they should focus on peace and goodwill. Katie takes the family to cut down their own Christmas tree. When Gaby picks the tree, it falls on her—just as Katie snaps some embarrassing photos.
Katie offers to take Gaby to her mom’s salon to make amends. Before they leave, Gaby notices a sign prohibiting logging, making her suspicious. At the salon, Katie accuses Gaby of trying to sabotage her relationship with Kevin. Gaby doesn’t buy her nice-girl act, and they exchange threats—Katie warning her to get on board or be left behind, and Gaby threatening to expose her true self.
Meanwhile, Kevin asks Chuck for his blessing to marry Katie. Chuck says no.
Gaby calls Nora to vent about Katie. Nora asks if she has proof of the past bullying. Just then, Gaby sees Katie has posted embarrassing photos of her online.
At home, Katie is helping Gaby’s mom make tamales—Gaby’s usual job. Tension rises as Gaby demands Katie stop tagging her in posts. Katie plays innocent, but Gaby insists she doesn’t need social media help. After trading insults, Katie leaves. Gaby decides to spice the salsa way up for Katie’s dinner.
At dinner, just as Kevin prepares to make an announcement, Katie eats the fiery salsa, tearing up. Kevin proposes, and Katie barely manages a "yes." Gaby is scolded by her parents, but she insists Katie ruined her childhood and is now ruining Christmas.
Gaby later shows Nora a video of Katie bullying her at a science fair, planning to show Kevin. Nora urges her to move past it. Gaby admits she never talked about the past with Katie.
The next morning, Gaby apologizes to Kevin, promising to make things right. He just wants her to get along with Katie.
Gaby asks Katie to talk about their past. She explains how hurtful Katie’s teasing was. Katie apologizes but reminds Gaby that she, too, was cruel—snubbing her for smarter students. Gaby hadn’t realized her part in it. They bond over their shared "mean girl" past.
However, downstairs, the family is watching the bullying video. Kevin is horrified and questions if he really knows Katie. Hurt, she insists she’s changed and leaves.
Gaby tells her mom that Katie isn’t a bad person and regrets damaging Kevin’s relationship. Clarice says Kevin needs their support.
At the festival, Kevin, as Santa, looks dejected. Gaby covers for him, but Katie arrives, announcing that Santa dumped her on Christmas Eve. Chuck jumps in to defend his daughter, but he and Kevin tumble off the stage.
Back home, the family is in low spirits. Gaby tries to lighten the mood, but everyone heads to bed. Alone, she attempts to finish her audition video but breaks down—just as the power goes out.