Single working mom Christine Campbell has just learned that her ex is dating a much younger woman with the same first name. To avoid any confusion, the new girlfriend is dubbed New Christine, which leaves her with the unfortunate nickname Old Christine.
Christine and Matthew fly to the Bahamas to get Barb an illegal visa after she was arrested by immigration during Richard and New Christine's wedding ceremony.
A trip with Barb to retrieve some of Richard's things sees Matthew worry that New Christine isn't letting out her feelings over the wedding fiasco. Meanwhile, Christine and Richard meet up with some of their friends from college and are shocked to see how badly they've aged.
Old Christine finds a suspicious mole on her left breast, and overreacts, thinking shes dying. Meanwhile, Richard tries to negotiate with New Christine regarding their house.
An aggressive divorce attorney is hired by Christine after being convinced that Barb owes her alimony.
Christine starts seeing a therapist who's Matthew's mentor, but they are both confused on whether they want to have a professional or romantic relationship. Richard and New Christine have trouble adapting to living under the same roof.
When Ritchie is asked to a dance by the most popular girl in school, Christine believes that she is popular by association and has finally surpassed the Meanie Moms. Meanwhile, Matthew and Richard find an apartment that they want to rent together. Unfortunately, they will have to find a way to evict an old lady that lives there before they can move in.
Max decides it's time to tell Christine that she quits anything that gets too hard for her, which includes relationships, and he points out that is the reason he chose to be her therapist rather than her boyfriend.
Christine has set up a date between Richard and a gorgeous, passionate woman who works out at her gym, while Tom (Richard's friend) continues trying to woo Chrisine.
Barb, afraid that a marriage proposal is iminent, asks Christine to run interference on her next date with Dave; Richard realizes he must try to woo New Christine if he wants her back.
Christine discovers that Ritchie has become a bully at school and attempts to change his behaviour by changing her own ways.
Christine learns a juicy neighborhood secret when reluctantly attending the Christmas block party.
Christine tells her therapist, Max, that she is in love with him, but his reaction is not quite what she is expecting.
Mr. Harris returns just as Christine starts falling in love with Max.
Christine asks Richard to have a baby with her after becoming envious of Richard and New Christine's happiness in planning for theirs.
When the gym suddenly begins to become profitable, Christine and Barb find themselves coming into a lot of money. Barb decides to give to charity, and Christine must make the tough decision between splurging on a designer dress or following Barb's lead.
In an attempt to teach Ritchie's class some street smarts, Christine encourages the school administration to let them take the subway on a field trip, but she ends up being stranded at the station when the trains leaves without her.
Christine realizes that Ritchie has never been on a real family vacation, so she plans a trip to Florida, with disastrous results.
Richard is secretly planning an impromptu wedding for him and New Christine, so to help him out, Christine drags a very cranky and pregnant New Christine to a fancy salon while he puts the plan together.
When Christine is told that her five-year car lease is up, she realizes that her life hasn't evolved during that time the way she'd hoped and decides to make some major life changes, with a little help from her boyfriend, Max. Meanwhile, Matthew seeks a roommate to replace Richard.
Christine mistakes a good looking cop for a stripper, who alerts her that there is a prowler in the neighborhood. In order to feel more secure, Christine asks Matthew to stay over. Meanwhile, New Christine goes into labor, with the sole goal of avoiding having the baby arrive on Old Christine's birthday.
When Christine has Matthew and Barb throw her a "surprise" engagement party so she can get to know Max's friends, she begins to feel intellectually inferior to one particular guest, driving her to make a "surprising" decision.
