Richard's request to Old Christine to get his engagement ring back to give to New Christine causes problems in their friendship, and Matthew falls in love with his first patient as a therapist.
An article about Barb in a black businesswoman's newspaper causes a large number of African Americans to join the gym, which makes Christine uncomfortable.
Richie is at the age of not saying I love you to his mother. Christine wants another baby so she has someone to say I love you. She asks her ex-husband Richard to get her pregnant. Meanwhile, Matthew says he can't stop saying I love you.
Christine and Barb put themselves back out into the dating market with mixed results, and Matthew regrets helping Richard pick out a chair for his wedding.
Christine's new relationship is in jeopardy because she keeps letting Richard tag along with them. Barb uses Matthew's new job as a therapist to reveal some disturbing secrets about herself.
Christine tries to prove to everyone that her new boyfriend is actually a psycho, and Matthew discovers that his new girlfriend looks a lot like Christine.
Everyone spends Thanksgiving at Christine and Matthew's parents' house. However, their father is not around, and their mother won't come clean about why.
Christine and Barb decide to turn their gym into a spa, but soon learn of "inappropriate activities" going on there. Meanwhile, Richard tries to make friends with all the female volunteers at Ritchie's school.
While attending a meeting to get Ritchie into a new school for seventh grade, Christine gets in trouble when she runs into a man who spread some dirty rumors about her when they were in seventh grade themselves.
Christine and Barb give New Christine a bachelorette party in Las Vegas, where New Christine lets all of her previous inhibitions go. Meanwhile, Richard, Matthew, and Richard's brother spend Richard's bachelor party playing laser tag.
Barb and Matthew both move out of Christine's house at the same time, so she tries to prove to everyone that she can make it without them. But was Matthew's decision to move in with his girlfriend a good idea?
Christine makes friends with a woman who is as needy and dependent on her as she is on Barb, and Matthew has a bad experience moving in with Richard and New Christine.
There is an outbreak of lice at Richie's school and he is one of the affected ones. Everyone thinks Christine and Richie are "patient zero". Tired of the hassles at that school, Christine looks for another school for Richie.
Christine and Matthew try to lose weight together, but only Matthew is successful. Meanwhile, Ritchie tells Richard that he doesn't want him to marry New Christine.
Christine tries to convince herself that her date for Richard and New Christine's rehearsal dinner isn't a total jackass, while Matthew hooks up with New Christine's sister.
Christine hooks up with New Christine's dad again before the wedding--and then finds out he's getting married. Also, Matthew finds out his new relationship is temporary, and Barb's new potential beau is forced to arrest her.
