When new mom Lucy welcomes guests over to see the baby, Annie immediately becomes concerned, believing that Lucy doesn't fully understand the health risks of exposing a newborn to strangers. Lucy's determination to show everyone that she has parenting under control leaves Kevin to question his role as a father, especially when they're alone. Also, struggling new parents Kevin and Lucy move back into the Camden home, while Martin moves into the garage apartment.

Eric is worried that he and Annie are doing too much in helping Kevin and Lucy adjusting to parenthood as they're taking on more than they should as grandparents. Meanwhile, Martin's classmate Zoe (guest-star Katie Cassidy) intentionally falls asleep on the couch of his apartment so that she can tell everyone at school that they slept together. When Ruthie finds out about Martin's overnight guest she sees it as the perfect opportunity to blackmail him into getting her a date with her crush, Vincent (guest-star Thomas Dekker).

Ruthie is on cloud nine when an emotional Eric and Annie reluctantly agree to let her go on her first official date. However, Ruthie isn't surprised to find the family handling her big news with their usual crazy Camden ways: Annie and Lucy decide it's their job to help Ruthie prepare for her date with Vincent (guest star Thomas Dekker); Kevin takes it upon himself to give Ruthie ""the talk""; Sam and David change into their Sunday best so they can go on the date as well; an overprotective Martin and Mac (guest star Kyle Searles) decide to spy on Ruthie and Vincent's date; and Matt volunteers to play chaperone, but finds himself in a web of lies to protect Ruthie's feelings.

The streets of Glenoak are alive with the sound of music as the Camden family breaks into song for a very special Valentine's Day musical episode. Classic songs (""Love Is Sweeping the Country,"" ""You Were Meant For Me,"" ""Nice Work If You Can Get It,"" among others) are performed by the Camdens.

Simon is enjoying having his new girlfriend, Anna, who he just met the day before over at his apartment for Valentine's Day. They both agree to go to Glen Oak, but he decides to keep her away from his family for the time being. Annie displays her unhappiness to Simon in song (along with the rest of passerbys) over his constant dating habits at the promenade as the chorus is going on. Anna overhears this and begins to question Simon and his dating habits as well. Vincent confronts an unhappy Ruthie on the high school bleachers as she's not in the Valentine's Day mood and is upset over watching Martin practice with his team and Zoe blowing kisses at him.

Also, Lucy and Kevin dance to ""You Were Meant

Although he practices safe sex, Simon panics when his girlfriend of the moment, Sandra (guest-star Olivia Allen), confesses to him that she has an STD. Meanwhile, Martin and Mac (guest-star Kyle Searles) catch Ruthie's boyfriend, Vincent (guest-star Thomas Dekker), on a date with another girl. Also, Matt, Lucy, Kevin and Ruthie have second thoughts about telling Eric and Annie that Mary (Jessica Biel, who does not appear in the episode) is pregnant again, but also to hide the fact that she has deserted her husband Carlos and her baby son Charles. Lastly, Annie decides to go to New York to pay Mary a visit.

A non-church patron Marie enlists Eric's help in handling her elderly mother, Mrs. Wagner into getting her into a nursing home, but Eric gets a different impression when he finally meets Mrs. Wagner and sees that she doesn't need help and is still very capable. In fact, it turns out Marie may need more help than her mother as she's very unhappy with her life. But things turn out bad later on when Mrs. Wagner ends up in the emergency room due to her stress from her daughter.

Ruthie puts up a fight with Lucy while shopping as she wants to spend the day with Vincent without Annie knowing about it. Ruthie wants to go to a family dinner with Vincent. Although, it inevitably blows up in her face and leads to an interesting conversation with Annie and Lucy in the driveway.

Ben (guest-star Geoff Stults) shows up in Glen Oak to pay Kevin and his new family a visit and makes himself well at home again in the garage apartment. But Kevin is not happy to see his brother as he wanted his mom and hus

After being taunted for wearing second-hand clothes at ""Second Hand Rose"" by Vincent's (guest-star Thomas Dekker) new girlfriend, Margot (guest-star Ashley Benson), a distraught Ruthie runs into the bathroom and finds Martin's girlfriend, Zoe (guest-star Katie Cassidy), recovering from a fainting spell as two girls try to help her. Zoe confides that her family doesn't have enough money for food and makes Ruthie promise not to tell anyone.

However, when Martin breaks up with Zoe because he doesn't like her conceited attitude, Zoe thinks Ruthie has betrayed her confidence. Meanwhile, Kevin unsuccessfully tries to create some alone time with Lucy, but is frustrated with Lucy's obsession over Savannah. Also, Eric and Annie suspect that Sam and David are feigning being sick so they can stay up late and eat sweets. Lastly, Sam is jealous of the attention being given to an ill David.

An extremely nervous Simon comes home to Glenoak to await the results of his STD test. Eric counsels a woman (guest-star Erika Alexander) who is caring for her two daughters (guest-stars Bree' Anna Banks and Brandi Vanice) with sickle cell anemia and whose absentee father (guest-star Victor Love) is hoping to take them back with him to Memphis for treatment at St. Jude Children's Research Hospital.

Meanwhile, Ruthie's ex-boyfriend, Peter (guest-star Scotty Leavenworth), pays her a surprise visit, which creates problems with her current boyfriend, Vincent (guest-star Thomas Dekker). Lucy and Kevin disagree over who should care for Savannah when Lucy returns to work. Lastly, Martin misses an important call from his father in Iraq while sneaking out of the house to be with his girlfriend.

After discovering that Mary (Jessica Biel, who does not appear in the episode) has filed for divorce and signed away custody of her son, Matt is at a loss for how he should to break the awful news to Eric and Annie. Simon informs his new girlfriend, Rose (guest-star Sarah Thompson), that he won't have sex with her, but avoids telling her the reason behind his decision. She gets fed up with him but comes back to him when she finds out his true intentions for them---marriage. Meanwhile, Ruthie's boyfriend, Vincent (guest-star Thomas Dekker), asks Martin to get Ruthie to break up with him.

Also, Eric gets involved once again with the Davis family children when little boy Danny (guest-star Drake Johnston) is being adopted by Cecilia's parents, George and Gwen (guest-star Brad Maule and Holly Fulger), but forgets to mention that the kid is part of a package deal as Danny has three sisters in Social Services as well, and try to take them in as well. Kevin is about fed up with Lucy as he's fr

When Simon and his new girlfriend Rose (guest-star Sarah Thompson), make an unexpected visit to Glenoak to meet their respective parents, Annie begins to suspect their relationship might be on a fast track. She let's them know they are not allowed to sleep in the same room together in the house as they spend the night. Rose puts up a fight with both Annie and Simon over the sleeping arrangements, but eventually take will. Meanwhile, Eric hides the news of Mary's (Jessica Biel, who does not appear in the episode) divorce, worried that it will most certainly break Annie's heart.

Also, Martin becomes the third wheel again in Ruthie and Vincent's relationship as Ruthie thinks Martin is jealous of their relationship despite the fact that Vincent wants Martin to convince Ruthie to dump him. The adoption process for George (guest-star Brad Maule) and his wife over the Davis children becomes more complicated when their biological mother fights for the adoption process to not happen. Lastly, Ma