Lucy, Kevin, and Savannah move back to her parents' home where there is one mother too many. Annie tries to impart her mothering skills on Lucy, who has different ideas. Ruthie sees an opportunity to get a favor from Martin.

Ruthie is going on her first date, and everyone else is more worked up than she is.

The cast shows their singing skills as the express their feelings about Valentine's Day. Simon starts dating another gal. The twins celebrate their birthday.

The Camden kids panic about their cover-lie for "Simon's" (actually covering for fickle, unfaithful Mary's) secret after Annie phones with Carlos; she doesn't learn it yet, but decides to surprise-visit Mary in New York excited about the fictitious baby; the following family calls only weave the web of deception and misunderstandings ever tighter, even gold-honest Kevin gets ragged in; even when Eric's overhears an unclosed line, he keeps it secret for Annie but visits Simon, also on false pretenses. After dragging it out of Ruthie, Martin wisely abstains from compounded lying. Martin and Mac, who sort of hopes to get her on the rebound, catch Vincent dating another girl, but only to make Ruthie jealous, who brushed him off with a lie, next Vincent goes make up with her.

Ben Kinkirk practically invites himself to stay with brother Kevin to see Lucy and their baby, knowing absent Martin's apartment is available that weekend, and speculates about him dating Mary again now she has left Carlos. Annie has the morbid obsession that the family should attend a 'birthday party' for her late mother Jenny. Ruthie would rather spend that time with Vincent, and she runs a plan by Lucy while they shop for flowers. Meanwhile, Eric tries to help career woman Marie Wagner work out how to handle her mother's worsening physical and mental health.

Lucy seems to only have time for Savannah, and Kevin feels left out. Vincent's new girlfriend is a snob who looks for ways to insult others. Zoe confides in Ruthie that their family does not have enough money for food. The twins are sick.

When Simon visits home to write a paper, the twins are just happy, the sisters speculate what trouble he's in; dad guesses his Bible reading is a pact with God for a clear bill on his venereal disease test. Zoe convinces Martin to join her watching a meteor shower for an astronomy assignment, but he leaves his cell phone afraid to tell Eric as it's at night, and thus misses a persistent caller- from Iraq. Lucy wants to return to parish work, but Kevin refuses to dump their baby on her ma, even prefers doing night-shifts or becoming a home dad. Ruthy's ex Peter Petrowski's parents George 'Vic' and Paris ask Eric to remarry them. Ruthy's boyfriend Vincent is offended she nags about Peter saying not to feel anything for her anymore.

Cecilia's dad George Smith tells Eric that he and his wife Gwen are looking for a foster-son, about 10 years old, to fill the now empty-feeling home, with the hope of adopting. The enthusiastic reverend immediately thinks of orphanage boy Danny Davies, who proves charming and eager. Danny expects to that his sisters will be adopted too. It's only fair that Eric helps put that straight, which proves even more complicated then it sounds. Carlos tells Matt he's leaving New York for his dad's firm in Puerto Rico because 'mother' Mary makes no marital effort at all, having cheerfully signed over custody of baby Charlie. The twins are sad that Martin, and in time all their siblings seem to leave, even Lucy now. Kevin presses her to finally choose a house, then concludes the mother is the one who pushes fledglings out of the nest. Simon's girlfriend Rose wants to dump him unless he gives a good reason why they still don't have sex. Vincent pushes Martin to help him break up with Ruthie, in case he meets a girl while on vacation with his grandparents on Hawaii.

Eric hides Mary's divorce from Annie, and Simon's romance heats up. While the Smiths brace for a custody battle over the Davis kids, Simon arrives home for an overnight visit with his girlfriend Rose (Sarah Thompson), whom Annie finds "condescending and rude." Annie's intuition tells her Rose is pushing Simon for marriage, and that something's up with Mary and Carlos. Although Eric knows Mary has filed for divorce, he avoids sharing that information with Annie just yet. Since Vincent doesn't have the guts to break up with Ruthie, Martin takes it upon himself to reveal the truth. Lucy is surprised by Annie's erroneous assumption that Carlos and Mary are still together. Meanwhile, Simon hears from Kevin that Rose had led Annie to believe they're engaged. When Simon confronts Rose, he reiterates that, even if they discussed the possibility of marriage, he didn't actually propose. Visibly upset, Rose walks off. The Davis kids are stunned to learn their mom is refusing to relinquish custody. As much as they want to be adopted by the Smiths, the children fear that if they testify against their mother in family court, she'll wind up turning to drugs and alcohol. That's not a risk they're willing to take. Later, Ruthie asks Vincent to never call her again, and Rose asks Simon what he wants from their relationship. To Kevin's delight, Lucy puts an offer on a fixer-upper house next door! The Smiths and Davises reach a compromise: George and his wife won't push for adoption, but Mrs. Davis will allow them to become the kids' foster parents. Minutes after Eric shocks Annie with the news of Mary's divorce, Simon and Rose announce they intend to get engaged "in the near future." That evening, the Camdens join Martin as he welcomes his father home from Iraq. .. _