Billie hosts Christmas for her family and parents, but she has not told them that Zack lives there wither her and tries to keep it a secret. Abby's husband Nick tries to impress their father, with little success. Davis and Zack leave on their holiday adventure, but when Davis figures out that Zack really wants to be with Billie, he surprises him by taking him home where he interrupts the holiday, to Billie's shock. Billie tries to keep the charade, but her father sees through it and figures out that Zack loves Billie. At dinner, Zack proposes to Billie.