When Heidi crashes Laurens surprise birthday party, the two old friends cry about their disintegrated friendship. Spencer starts a violent fistfight when Cameron accuses him of picking up a bartender.

Spencer's flirtatious ways lead Heidi home to Colorado, where she reconnects with an old boyfriend. Lauren gives Stephanie a piece of her mind for inviting Heidi to her birthday party. Spencer ends a long silence with Brody.

After Heidi catches Spencer at a nightclub with Stacie the bartender, she demand's they go to couple's therapy. Lauren puts her reputation on the line when she gets Stephanie an internship at People's Revolution.

Audrina tries to get over Justin by setting her sights on Brody. Heidi drags Spencer kicking and screaming to couples therapy. When Stephanie screws up at People's Revolution, Lauren threatens to fire her.

Audrina tries to get over Justin by hooking up with Brody when the girls crash the boys surf trip to Hawaii. Heidi's virgin ex-boyfriend comes to visit and she hopes some of his values will rub off on Spencer.

Audrina is heartbroken when BrodyâEUR(TM)s girlfriend confronts her about Hawaii, and Brody does nothing to stop it. Heidi intercepts a text message from Stacie to Spencer and goes to a nightclub to confront her.

Justin confronts Audrina about hooking up with Brody in Hawaii. Stephanie ruins a photo shoot at work, which means Lauren will have to answer to Kelly. Stacie the bartender tries to make peace with Heidi.

Spencer tries to save his relationship with Heidi by asking her cowboy dad's permission to get married. Lauren must fire Stephanie from People's Revolution, risking their friendship.

Lauren thinks twice about going to Heidi's wedding after Spencer finally apologizes. Brody refuses to risk his relationship with Jayde to save his friendship with Audrina, and Stephanie confronts Kelly Cutrone.

In Lauren's final episode, she must decide whether she's willing to forgive Spencer in order to be there for Heidi on the day of her princess wedding. The entire cast shows up and is shocked by a guest no one saw coming.

Kristin Cavallari's attempt to reconnect with her Hollywood friends goes awry when she angers Audrina by hitting on Justin. Heidi and Spencer embark on married life by shopping for a new house.

After being stood up by Audrina, Kristin decides to stop fighting her attraction to Justin. Heidi volunteers to babysit the next door neighbor, but Spencer wants nothing to do with kids.

Kristin gets her first taste of being in a relationship with Justin when he doesn't show at Brody's surprise party. Heidi and Spencer disagree about when to start a family, and Audrina goes on a date with Justin's best friend.

Kristin thinks she has tamed Justin Bobby, but Justin may not be over Audrina just yet. When Holly loses control at an event, it's up to Heidi to make her sister confront her drinking problem.

Justin plays hard to get with Kristin, but his plan backfires. Holly's drinking leads to an intervention by Heidi and Stephanie. Brody and Jayde get in a fight that leads them to reconsider their relationship.

Justin finds himself in hot water after Kristin and Audrina finally meet face-to-face. All Heidi wants for her birthday is a baby, but Spencer has something else in mind.

Kristin and Brody consider dating again. Audrina and Justin meet to discuss their future, but it doesn't end the way she hoped. Spencer takes the most drastic measure yet in his ongoing war with Heidi over starting a family.

Kristin clashes with Jayde when she comes back to reclaim Brody. Heidi hatches a plan to get pregnant with or without Spencer's consent; Audrina copes with the fact that Justin still has feelings for Kristin.

A wild weekend in Las Vegas makes Kristin wonder if she has real feelings for Justin. Spencer comes up with a plan to find out if Heidi has stopped taking her birth control.

Kristin decides she doesn't want a relationship with Justin. Audrina finally frees herself from Justin. Brody gets cold feet when Jayde wants to move in with him, and Spencer sweats the possibility Heidi might be pregnant.