Lauren lands in tears during her surprise birthday party when Heidi rocks the boat by showing up uninvited. Plus, Spencer takes a swing at Stephanie's ex-boyfriend, Cameron.

Heidi and Spencer evaluate their relationship after the bar scene and Lauren scolds Stephanie for pushing Heidi on her.

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

As Audrina tries to get over Justin, she sees Brody in a new light. Plus, Heidi drags Spencer to couples' therapy and Stephanie has a hard time handling work at People's Revolution.

Things heat up between Audrina and Brody in Hawaii and Heidi's ex-boyfriend, Colby comes for a visit.

The gang make their return to Los Angeles. Meanwhile, Brody and Audrina deal the repercussions from their hookup in Hawaii.

Lauren is put into an awkward situation after Stephanie messes up at work. Meanwhile, Justin calls out Audrina for hooking up with Brody.

Spencer has an important question to ask Heidi's father when he comes for a visit. Meanwhile, Lauren make the decision to fire Stephanie from People's Revolution.

Spenser is asked by Heidi to make amends with Lauren in hopes that she'll attend their wedding. Elsewhere, a recently fired Stephanie has a run-in with Kelly Cutrone, her former boss.

Heidi and Spencer head down the aisle and two unexpected guests manage to attend the ceremony.

Kristin makes a big first impression in The Hills when she gets in a fight with two different women over one guy, works her way to queen bee status and lands a hot date with a motorcycle all in one episode.

Kristin kicks her pursuit of Justin into high gear after Audrina blows her off, while Heidi and Spencer's opposing views on kids causes trouble.

Justin tries to make up with Kristin. Heidi thinks something is wrong with Holly.

Heidi and Stephanie sit Holly down for an intervention when she continues drinking. Plus, Kristin gets upset with Justin's head games and Brody and Jayde get into a fight that leads them to reconsider their relationship.

Justin finds himself in hot water after Kristin and Audrina meet. Heidi wants to have a baby, but Spencer has another plan.

Audrina gets her heart broken when Justin ends things for good, it's a war of the exes over Brody, and Spencer considers drastic measures to stop Heidi's baby obsession.

While on a lunch date, Kristin and Brody recall the crazy times they used to have together. After Brody toasts to having a nice lunch without fighting, Kristin mentions that Jayde wants to talk with her. Brody tells Kristin she's out of her mind ...

Kristin and Stacie's girls' weekend in Vegas becomes a threesome when Justin joins the fun. Plus, Spencer panics when he uncovers Heidi's pregnancy scheme.

Kristin is in Malibu packing up her beach house when she tells Stacie she doesn't want to pursue a relationship with Justin Bobby. Kristin says things were perfect when they were in Vegas, but she knows real life isn't like vacation.