In the third season-opener, Annie is feeling a little depressed since she's 3 months pregnant. Ruthie is pretending to feel a little pregnant herself. Lucy is following the dating advices from 'The Rules' book she has. Matt moves in an apartment with three attractive girls. Eric is looking for the perfect 20th anniversary plan for Annie. Mary gets a lot of attention from guys, which makes Lucy jealous. Although, one of Mary's 'guy' friends asks Lucy out. Matt finally comes back home because of girl problems he was having with his new roommates. Simon's girlfriend is acting a little weird. Eric and Annie tell the kids they're having TWINS!

Annie's father, Charles is getting married to his girlfriend Ginger. The wedding reception is supposed to be at the Camden's house and Annie is the one in charge of preparing the menu. Annie isn't enthusiastic about the wedding and the reception. On her way to the grocery store, she meets a homeless veteran and invites him home. He is the one ending up preparing the menu since he was a chef for forty years. Also, Matt and Mary are taking a little road trip, which ends up being very long when they get a flat tire. Simon is spending the day with his new girlfriend Deena. Lucy is spending the day with Jordan, the guy she can now call her boyfriend. Lastly, Ruthie is feeling lonely, so she pretends her imaginary friend Huey is back the whole day.

Ruthie wants the ""Booboom"" video game that her friend has and is walking around the house pretending she is dropping bombs which is annoying Annie a lot. Simon has a BIG problem at school when his girlfriend Deena tells him that her former boyfriend Johnny just got dumped by his girlfriend and might be coming after him so he could get back together with Deena. Johnny then threatens to shoot Simon the next day at school. Simon tells Eric this and tries his best to settle this matter leading to bad consequences on both sides as someone gets shot. Meanwhile, Matt introduces Mary to his friend Shana and her brother. He asks Mary out on a date, but has no idea that he has a BIG problem--- he is violent. Meanwhile, Lucy tries to be romantic with Jordan and wants to slap him after watching ""Gone with the Wind.""

Eric and Annie are taking prenatal classes--- for the sixth time. Annie helps two teenage girls get through their pregnancy while Eric helps the two teenage fathers deal with the news and finding a job. Simon is taking babysitting classes and gets his first job babysitting Ruthie, although it doesn't go quite the way he expected it to. Meanwhile, Mary is sneaking to a coed basketball sleep over. Plus, Lucy is thinking of having sex with Jordan to see if he's really attracted to her, but it blows in her face. Lastly, Matt has to do research on sex for his class and is having trouble over finding a topic..

It's the Christmas season and Eric has his three oldest children doing charity work for the community. Mary and Lucy aren't enthusiastic about the charity work that Eric wants them to do. Mary is working in a soup kitchen while Lucy has to organize auditions for the ""Live Nativity"" at the church. Meanwhile, Eric has given Matt a well-paid job as Santa Claus at the mall. Also, Simon is in the spirit of wearing his VERY tight candy cane pajamas and wanting to put on lights inside the house since he's not allowed to do it outside alone. As a family ritual, each family member picks a name out of a hat of who to get for Christmas while Eric and Annie cheat. Before going on his family vacation, Jordan accidently gives Lucy a gift that was meant for his uncle's monkey (shoe shine-kit), but was supposed to give her a basketball signed 'I Love You'. Also, Mary meets a a guy, Carlos at the soup kitchen who doesn't have a place to stay for Christmas, so Mary invites him to stay over at their hous

Samuel and David are home and won't stop crying. Matt gets a new job at the Dairy Shack as a delivery guy. Mary sneaks to the pool hall to meet Wilson while Lucy covers for her at home. Lucy ends up doing all the cleaning by herself. Mary hangs out with Jordan as Wilson arrives. Wilson is thinking of moving back to Glen Oak, but Mary realizes she doesn't have feelings for him anymore. Ruthie wants to run away from home because she doesn't get much attention as she used to. Annie gives Ruthie her baby book. Simon orders food from the Dairy Shack to check out Matt's new job. Matt is fired from his job and meets an old girlfriend, Shana.

Eric worries about Matt as Heather's wedding approaches. Eric learns that his sister Julie is dating Dr. Hastings (the doctor who delivered the twins and almost killed Matt at birth) without telling him or the family. Also, Lucy and Simon are both in their awkward love triangle between all of their two best friends and lovers. Ruthie wants to be a bridesmaid and a bride at Heather's wedding.

In the third season finale, Eric counsels an engaged couple facing difficulties. Mary, Lucy and Simon learn the repercussions of forbidden love, especially Simon when he is caught in his bedroom alone with Deena kissing near his bed. Julie gets married to Dr. Hastings (Hank) and learns that she's pregnant. Also, Heather breaks up with her fiance after she learns he was cheating on her with another woman. Matt tries to save his relationship with Shana after he ran off with Heather, and does this through his pleading of forgiveness.

Mary's feelings for Robbie resurface when she inadvertently finds out he has a secret date for Valentine's Day, and the whole family schemes to uncover the mystery woman. Meanwhile, with the exception of Lucy who has a date with Jeremy, the other Camden kids feel deflated when their Valentine's plans fall through and they end up stuck at home celebrating Sam and David's second birthday. Lucy and Jeremy's first date does not go as expected as they both keep on running into Lucy's ex-boyfriends. Although all's well that ends well by the end of the episode for everyone.