Simon has another hot date, college girl Marcia, but when Matt turns up as driver, she only has eyes for the med student, although Simon gets the porch kiss. Lucy dates and agrees to go steady 'light' with Mike Pierce, whom she met in a dean's office, where he offered to help her apply to colleges, but doubts again after learning about his mental history. Their parents found none of the kids still interested in family movie night, nut discover too late sneaking off for 'intimacy' never goes unseen, this time even worse. Mary nearly gets arrested with teenage parents Johnny and Frankie, who are caught smoking marijuana just after her visit.

Simon lets his mate Luke set them up with the Murphy twins, who fall for his cool 'bad boy' image by association with Mary, but the vixens make the knaves join them in shoplifting and other mischief. Matt falls in love at first sight with a girl in a wedding dress, actually model Julie. Only Mike teaches Lucy how to handle gossip. Annie seeks comfort with a friend, positive thinking guru Robin, who turns out rather negative.

Robbie and Cheryl ask Eric to marry them because of her pregnancy. He smells a rat and learns just in time that she intended to trick Robbie, who is grateful to escape a loveless marriage and offers to stay away from Mary. Lonely Simon has joined punk Norton's schoolmates gang. Lucy, who is lightly butt-slapped, and the Camden parents, make huge scenes over inappropriate remarks from some of the knaves, treating Simon as if he 'hates women'. Matt tries to help both sides understand, but fails, yet a real incident shows Simon's truly good nature. Matt can go for Priscilla after hearing from Heather she's dating another already.

Robbie's ma lost her house and moved away without him and moving in with Cheryl also fell through, so Eric finds him studying outside, yet keeping up top marks. He promises to find a shelter and takes him home meanwhile. Despite embarrassing episodes, all the fault of Camden girls, Robbie proves himself a model house-guest. So Matt finds the couch occupied when chased from his dorm by John, who is completely besotted with Priscilla Carter. Simon keeps is foxy new date Sasha a secret until she arrives in a BMW. Lucy is passively jealous when Mike Pierce announces he got early college acceptance, then goes over to make up and thus discovers his ma's disabling mental condition.

Eric threatens Robbie with eviction because he thinks he's keeping secrets about Mary. The house is abuzz with secrets and preparations for an elaborate surprise party for Eric's birthday. Johnny drops Mercy on the Camdens' doorstep after Frankie abandons them. Mike trusts Lucy enough to look after his mother for a day, during which the woman surprises her, both by speaking and by what she says.

Robbie is not amused by week-long roommate Matt's jealous whining, but still helps him make up with John, who lacked the courage to tell Priscilla her 'Japanese' room remodeling disgusts both guys. Mike decides after a kiss without chemistry to trade in Lucy for Elaina Casey, while matching Lucy with Mike's friend Jeremy. Simon and Robbie prevent suddenly jealous Lucy's reactions spoiling the whole partner-switch, which thus ends well.

Matt is terrified when summoned stat for a psychological session, standard for med students. After an unsatisfactory attempt to be 'coached' by therapy-experienced Mike, Matt lands with Doc, who turns out to be fraud and yet a godsend. Simon wants to break up with older, yet immature Sasha, but lets various advice how to go easy on her complicate things for him. Eric confronts a rather blunt hospital doctor about what to tell terminal patients like Harold Mann about their life expectancy and why.

Robbie panics when Mary announces she's returning for the summer months, so he tells her to follow parental instructions not to date her all that time. Mike inspires Lucy how to stay with Jeremy now he's accepted to Juliard: marriage, so they get engaged. Matt is dumped by Cheryl for not telling the family about them, but that gives him the courage and more reward then he bargained for. Wilson was dumped but traveled all the way home, just when Mary's claim of sexual intimacy with Jeremy make Robbie deck Lucy's equally startled fiancé. Simon and Tim discover Deena dated each of them behind the other's back. Serena abuses her lonely birthday to make a move on therapist Eric, while hardware shopkeeper James Carver courts long-oblivious Annie.

Robbie gathers the courage to tell Mary openly, now her lies are exposed, their relationship is over, staying with the family his priority. Simon nurses his broken heart on account of Deenah, refusing to become 'just friends' again. Wilson bonds, while bunking, with Matt and Robby, and demands for Mary to return and go steady in New York, or break up completely. Jeremy forgives Lucy for doubting her fiancé's fidelity. Ultimately Eric helps her transfer to his New York alma mater, near Juliard. The Camden parents finally realize Serena and James are seducing them, ward off each suitor and match the lonely hearts.

The next Valentine's day, Robbie prepared a surprise for Joy. Mary meanly supposes the hotel she overheard him contacting by phone means another sex trap. Joy, who assumed the butler to be away like her father really is, isn't discouraged, but bitterly claims Robbie doesn't love her truly because he refuses to risk getting intimate. Matt contacts all his 'true lovers', wondering why he never stayed hooked up. Lucy again assumes Jeremy, who is back in town and double-dating with Mike, wants her back and pretends to have a date. Mary is shocked to see Wilson moved back and goes steady with her former school friend Corey Conway. Simon gets permission to let his hot senior date Maria 'help babysit' and gets her cute kid brother Jake to spare Ruthie dateless embarrassment.