At Snackbar, Heidi's having lunch with Stephanie when she casually mentions Lauren's upcoming birthday. Stephanie tells her that Lo and Audrina are throwing her a surprise birthday party on a yacht, and Heidi is surprised that neither of them thought to invite her -- after all, she and Lauren have been texting and on speaking terms recently. Stephanie shrugs it off invites Heidi to come with her, and assuring her that it will be okay.While picking up Lauren's birthday cake, Lo and Audrina make sure all the plans are finalized for the party. When Lo asks about Justin, Audrina explains that the ring he gave her was meaningless and trip to Palm Springs was the limit to his better behavior, so she didn't bother inviting him to the party. Heidi comes up in conversation, and they both agree that although she's been trying really hard to be Lauren's friend lately, it was best not to invite her.At Heidi and Spencer's Apartment in Hollywood, Heidi gets ready for the party and still wonders whether attending the party will be cool with Lauren. Stephanie says it should be fine, but asks if Heidi told Audrina or anyone that she's going. Heidi says she didn't tell anyone--including Spencer. When Spencer walks in and asks what they're up to for the night and Heidi tells him that Stephanie planned a girls' night, mentioning that Lo and Audrina will probably be there. Spencer asks, "So is the queen bee-otch rollin' or what?" Heidi casually says she thinks so, and with that, Spencer leaves saying that he's got his own guys' night to catch up on.At the Marina Del Rey, the girls arrive in a limo with Lauren blindfolded. While Lo and Audrina guide Lauren onto the boat, Brody quiets everyone down inside. When she enters, everyone yells, "Surprise!"At The Dime in Los Angeles, Spencer keeps busy by checking out the bartender, Stacie, to which his friend Charlie comments, "I saw that...blatant!" Spencer asks Stacie what shots they should do, and she suggests Patron. Spencer goes on to tell her that the last time he had Patron, he got married in Mexico, but points out that it was apparently not a legal marriage. The three of them each take their shots, and Stacie laughs, "I think this is gonna be a long night."On the yacht, Heidi and Stephanie arrive and wish Lauren a happy birthday. Stephanie asks Lo if it's okay that Heidi came, explaining how badly she wanted to come, and Lo shrugs it off, "If she's here, she's here." Lauren comes up between Stephanie and Lo with a smile and asks, "So fun question...which one of you invited Heidi?" Stephanie jokes that Lo did, but Lauren adds, "I know Lo didn't, I was just kind of being like...nice."While Heidi looks for greater assurance from Audrina about whether Lauren is alright with her being there, Stephanie tries to point out to Lauren how hard Heidi is trying to be her friend again. She explains that Heidi is her own person outside of Spencer, but Lauren argues that it's not fair for them to be friends if the terms of their relationship are that Heidi can't mention Spencer. She says that sometimes people just can't be friends. Meanwhile, Lo tells Heidi that Lauren is uncomfortable with her being at the party, and Heidi vents her frustration about feeling stuck between Lauren and Spencer. Lo states that there's just a certain point where she has to move on and do what's best for her.Back at The Dime, Spencer continues downing shots when he notices Cameron, Stephanie's ex-boyfriend, walk in. After telling Stacie all about him, he walks over to Cameron's table, where Cameron asks, "Where's the wifey?" Spencer points out that it's guys' night out, and when Cameron goes on to ask about Stephanie, Spencer says simply that last he heard they were on the outs and he just doesn't ask her about those things. With that, Spencer returns to the bar and asks Stacie what gets her up on the bar dancing. Stacie tells him "Pour Some Sugar on Me," to which Spencer says, "You naughty thing, you."On the yacht, Stephanie receives a text from Cameron telling her that Spencer is trying to hook up with the bartender. When Heidi comes over and asks what's wrong, Stephanie explains the text message. Heidi gets upset, and she and Stephanie walk outside together while Audrina fills Lauren in on what just happened.Still at The Dime, Spencer gets a call from Heidi asking if he's flirting with the bartender, telling him all about what Cameron told Stephanie. Spencer gets defensive and says that's ridiculous, then tells her that Cameron is going to get beat up just before hanging up. Charlie tries to tell Spencer to forget about it, but Spencer insists, and goes to pull Cameron aside. He asks him why he's getting in his business, and Cameron argues that he's hitting on the bartender and Heidi deserves to know. Spencer starts taunting Cameron, yelling for him to touch him first but Cameron refuses, until Spencer finally starts punching him until the fight gets broken up.News travels to the yacht quickly about Spencer and Cameron's fight, causing Heidi to get upset again and walk out. When Lauren goes to comfort her, Heidi apologizes, saying that she didn't want to be the party crasher and then cause all this drama, and just wants things between them to be normal. They both start to cry, and Lauren explains how much she cared about Heidi, but Spencer still stands squarely between them. They both say that the last thing they wanted was for their friendship to come to this, and finally they hug. Heidi says, "I don't know what we're supposed to do." Lauren suggests, "Maybe we can just have a drink, and then we go from there."