After admitting that he had, Scott tried to defend himself, saying, "Obviously, we're both trying to move on. That's what we've all been saying. So I'm trying to do everything I can f**king do to not think about her."
The embattled reality star tried to defend his actions, claiming that, in order to emotionally cope with not being able to get back together with his ex, he "had to go back to a different lifestyle," which includes drinking and hooking up with random women.
"Then you shouldn't have come on a family vacation if you can't go four days without bringing some random girl in," Kourtney fired back. "That's just not cool."
"So let me f**k you then, and I won't have to do s**t like this," Scott yelled, before claiming, "I'm a sex addict! I'm a f**ked up, horrible sex addict."
However, Scott admitted in a solo interview that his claim was mainly just to defuse the tense confrontation.
"Saying I'm a sex addict is honestly the first thing that popped into my head, and I don't really think it's my actual problem," he explained. "But it's definitely not easy to hear everybody attack me and tell me how disrespectful I am, and I don't know, literally, what else to say."
Khloe had no interest in Scott's claims, and made her frustration known with a shower of ice water.
"If you need to get your d**k wet that badly, then get your f**king d**k wet," Khloe said as she stood up and threw a full glass of water in Scott's lap before walking off. Kim followed her after throwing another glass of water in Scott's face.
After most of the water had been thrown and most of the people had left, Scott walked up to Kourtney as she was leaving and laughingly said, "So, should we head home together? You and me?" His advances were roundly rejected.
Despite their conflict, spirits seemed to remain high between the sisters and Scott, and Kourtney said the dinner actually helped her feel better about the situation.
"I definitely feel relieved that we had that conversation at dinner, and now I can move forward," Kourtney said in a solo interview. "It's been nonsense for 10 years, like up and down, so this is like the final door closed. We're done."
Later in the evening, Scott texted Khloe, admitting he knew what he'd done was wrong and asking if he could stay in her hotel room, because he didn't want to have to go back to where he was staying with the woman he'd brought out to Costa Rica.
While Khloe told him he'd have to figure things out for himself, the pair did meet up the next morning to talk, and Khloe admitted she's decided to forgive him.
"It's totally hard to stay mad at Scott, but also Scott and I were texting the whole night. He was so remorseful and felt like a piece of s**t. So what am I gonna do? Kick someone when they're down? He already gets what he did [was wrong], so we're good," she said in a joint interview with Scott by her side.
Later, the family -- including Scott, Kourtney and their three kids -- spent the day inner-tubing and playing in some of the hot springs pools, where they all got along like a sweet, happy family.
"Scott's so lucky because I'm the coolest baby mama on the planet, because [despite] the stuff he's done, I still allow him to come on our family trips," Kourtney said. "He's the
father of my kids and I want him to have these great memories and experiences with us."
"I think, after everything that's happened here in Costa Rica, Scott knows that it's done," Kourtney told the KUWTK camera. "But just saying those words lets both of us move on and just feel like it's done."