In order to promote abstinence, Ms. Glass gives each student a semi-robotic baby doll that can vomit and cry loudly just like a real baby to make her point about how serious and tough being a parent is and how many responsibilities parents have for their babies. Now, everyone must take care of their baby for a week in order to pass her class. Meanwhile, Sam realizes that Brook is determined to leave their home and Mike and go to live with her estranged mother. Sam feels guilty over this, and when Brooke's shaken dad opens up to her about how much Brooke and even Sam's mom Jane will miss him, Sam decides to try and do something about it. Emory is about to go to the special projection of TRON (1982), but his wicked tween sisters, who happen to be twins, arrive and he must babysit them. However, he's no match for them. The sisters, who call themselves M'n'M, decide to throw a big house party for the cool people in Emory's school and hire Nicole and Mary Cherry to help them, as well as teach them how to be the top mean girls in school. Nicole and Mary Cherry greedily accept the deal not realizing how determine the twins are to outmatch even them. To make time for this, Nicole and Mary Cherry leave their babies with quirky British professional nanny - Penelope Poppins, who turns out to have a sadistic secret side to her.