As Kristin and Stacie road trip toward Vegas, the ladies give squeals of excitement as they drive into view of The Strip. Though Kristin tells Stacie she feels a good weekend is in store for them, she doubts she'll hook up with anyone because of the Brody and Justin drama back home. Stacie encourages Kristin to use their trip to dump her L.A. baggage. Kristin agrees and proposes they attempt to find at least one guy to flirt with all night. Stacie ups the ante, suggesting they go on the prowl for more than one conquest. "You live and you learn, and then you go to Vegas," she says.In L.A., Spencer and Charlie are at a car wash. Spencer tells his friend about Heidi's surprise romantic dinner as they wait for his car. While Spencer gushes over his lingerie-wearing, dinner-cooking wife, Charlie has a more cynical take on Heidi's sudden domestic skills. Likening Heidi to a black widow spider going in for the kill, Charlie warns Spencer to watch out for her ulterior motives. Charlie says Heidi might be trying to get pregnant on the low. Spencer gets nervous but refuses to believe his wife would do that. So, Charlie recommends that Spencer test Heidi to see if she is prepping for pregnancy by tempting her with prenatal no-no's like sushi and wine.Meanwhile at the Palazzo hotel in Vegas, Stacie and Kristin are drinking champagne in their room and toasting to the new Vegas boys they plan to meet. While they pick out clothes for their night out, Kristin vows not to bring up Justin or Brody and declares she wants to meet new guys.Later in L.A., Spencer has brought Heidi to Katsuya for a date night. Spencer raises an eyebrow when Heidi forgoes sake, opting for sparkling water, and passes on their usual fish dishes in favor of steak. When the food arrives Spencer toasts to their trustworthy marriage.Kristin and Stacie's night out is a little more whimsical as they sit in Ghostbar at the Palms Hotel in Vegas scoping out potential hookups. They are approached by J. Rod and Jimmy, who amuse the seated ladies with some wild dance moves, but Kristin seems distracted. She tells Stacie she's going outside where she makes a call. Kristin doesn't reach who she's calling but leaves a voicemail saying she's putting herself out there for whoever would've been on the line.The next morning, Stacie comes into Kristin's hotel room and finds her friend in bed eating an ice cream sundae. Stacie asks her where she disappeared to last night, and Kristin tells her she just came up to chill. Although she had a good time at Ghostbar, Kristin wasn't feeling the guys there. When Stacie suddenly realizes Kristin's shower is running, she asks if she brought a guy back with her from the club. Kristin plays coy for a while but eventually admits a booty call was the reason for her mysterious departure. Just as the admission escapes Kristin's lips, the bathroom door opens and out pops Justin Bobby with a towel slung around his hips. "This trip just got crazy," Stacie says.While Justin is in Sin City with Kristin, Audrina is having dinner with his friend Derek in California. She tells him about her and Justin's relationship terminating conversation. After commiserating with Audrina, Derek tells her that Justin is in Vegas with Kristin and Stacie. Audrina doesn't mourn over the news. Instead, she calls Justin a douche bag she is truly over. "This is the last time you're ever going to hear me talk about him," she says.Back at the Palazzo, Justin is the casino having a drink with Kristin and Stacie. The threesome agrees to go to a strip club for their night out. Once they've solidified their evening plans, Kristin and Justin have a heart-to-heart about their shaky history. Kristin asks if he ever would have driven to Vegas for Audrina. "You kind of make me do things I don't usually do," Justin replies. Pleased with his response, Kristin makes it clear that she is not going back to Brody. Stacie interrupts the reconciliation talk to take shots with the couple before they head to Rick's Cabaret for a strip show. While there, the three cut loose. Kristin and Stacie receive lap dances while Justin watches, and Kristin shares a kiss with both her beau and friend.The next day in Hollywood, Spencer shows Charlie an empty pregnancy test box he found in the trash. Spencer says Charlie was right about Heidi refusing to drink alcohol or eat sushi at dinner. "I'm going to have a serious meltdown if she tells me she's really pregnant." Charlie makes light of the situation while Spencer has oedipal visions of his future spawn growing up and murdering him.Back at the hotel, Kristin and Justin are lying in bed. Kristin's voice is hoarse as they recount the previous night's debauchery. Kristin tells Justin she's really glad he came but wonders what will happen once they get back to L.A. They both agree to wait and see if their rekindled flame will remain hot in the Hills.