Billie unintentionally causes Abby and Nick to break up when she asks them to be Godparents. However, after a fun night on the town with Davis goes too far, Billie must stop Abby before she does something she will regret.
When Billie and Zack take instructional parenting classes separately due to their schedules, Billie goes with Olivia and Abby. However, the course quickly becomes a competition when Abby outshines Billie at all the tasks.
Worried that she'll ruin Christmas - as she has in previous years - Billie tries to hide from her parents the fact that Zack is living with her. Meanwhile, Abby's husband, Nick, tries to impress their father.
Abby and Nick have their respective significant others spend time with Billie and Zack to prevent them from finding out about the surprise shower they are planning. However, their plan backfires when both Billie and Zack dislike their new buddies.
Not wanting to sound like a nag, Billie manipulates Zack into doing chores around the apartment; however, her plan backfires when Zack takes the initiative to "decorate" the nursery. Meanwhile, to earn extra cash, Davis gets a job at a gay bar.
Billie invites herself to Zack's high school reunion but worries that she can't compete with his hot, ex-girlfriend in her pregnant state. Meanwhile, Olivia helps Abby host a party where they try to sell Abby's miracle youth juice.
After faking labor pains to get Zack out of a speeding ticket, Billie goes into labor - for real. Unfortunately, things take a turn when Zack gets busted by the officer they had initially lied to and is hauled off to the police station.