At the time of the trip, Kourtney Kardashian, 36, hadn't been in communication with her ex Disick, 32, but was constantly getting texts and pictures sent to her from others about him as he partied with girls and vacationed in Mexico.
"I just want everyone to stop bothering me with information unless it's like, an emergency," Kourtney said.
Kourtney's mom Kris Jenner then confronted her daughter, advising her not to push all her "emotions to the bottom" and also to leave her heart open to any possibilities.
"He's the father of my grandchildren," Kris, 60, said of Disick, adding that it was "inevitable" that Kourtney and him will be in each other's lives forever.
For now, though, the mom of three just wanted to focus on her kids and not on her love life.
"I'm not like, a dating person. I did the dating thing before Scott for like a minute and it was not for me," Kourtney said, adding that she wasn't sure if Disick was "the one" but used to think he was.
"I just got out of a nine-year relationship, I think the last thing I need is anyone in my life," she continued. (And she stayed true to her word: Later in the episode, she politely declined the attention she received from a male admirer at a nearby table during dinner.)
In an effort to take Kourtney's mind off of Disick and also to get her to realize "how bomb she looks," Kourtney's sisters Kim Kardashian West, 35, Khloé Kardashian, 31, and Kendall Jenner, 20, decided to set up a photo shoot for Kourtney.
"Scott is just jumping about with these random chicks and Kourtney is way flyer than those girls will ever be," Khloé said. "Just knowing you're a bad a-- bitch is what life is about."
Meanwhile, Kourtney and Disick's relationship wasn't the only one making waves on the island: Kylie Jenner and her boyfriend Tyga also created their fair share of drama – mainly surrounding Kendall, who was particularly upset that she wasn't getting to spend any time with her younger sister.
At first Kylie, 18, showed no signs of making amends, even telling mom Kris that Kendall was "so f---ing annoying" when Kris suggested the two spend more time together on the trip.
"I used to always have Kendall on my side and now she's always gone," Kylie said, adding that she developed a closer relationship with Tyga, 26, and now that's her "comfort zone."
Tyga, meanwhile, did his best to mediate, sitting down with Kris and Kendall to talk about the situation.
"You have to be patient with Kylie cause she makes her mind up about stuff," Tyga said.
Kylie quickly shut the trio down after overhearing them from across the patio, snapping at them and asking that they take their conversation elsewhere if they were going to be talking about her.
Eventually, however, she relented and admitted she had been "a little passive-aggressive towards Kendall" because she felt left out and neglected, especially after Kendall set up the photo shoot for Kourtney, which made Kylie miss her super-close relationship with her sister.
Later one night, Kylie finally sat down to talk to Kendall one-on-one, and after a slightly awkward discussion the two seemed to work things out.
"I feel bad that Kendall is hurt because I really didn't mean for it to be that way. Kendall always has so much going on in her life and I'm always with T so I didn't even think about it when I invited him," Kylie said, adding that she was going to make an effort to hang out with her more. (And she does: Later in the episode, the three went on a fun hike together.)
Once the famous family returned to Los Angeles, the Kourtney/Disick drama was back front and center after he randomly showed up at Kris' house when she was in the middle of a meeting with Kourtney, Kim and Khloé.
The sisters were shocked to see him since they apparently hadn't seen or even really heard from him "in months." They decided to all sit down together so that they could talk.
"It's so hard seeing my children on a trip – that was the first trip that I've never been on with my own kids," Disick started off by saying, explaining that he "got jealous and scared" and brought a bunch of people to Mexico to make himself feel better but it only made him feel worse.
"I realize I'm in the wrong, I've been in the wrong a long time," he continued, adding that he felt so alone after the death of both of his parents and his breakup with Kourtney this summer.
While Kim, Kourtney and Kris remained noticeably silent during the better half of the conversation, Khloé stepped up to the plate to defend her sister, telling Disick they all still loved him but that he couldn't shift the blame around and should accept it himself.
"You say you don't have a family and you don't have all these things, we give you one, why do you like, destroy it?" Khloé said.
Disick went on to tearfully apologize for his actions, for letting down the family and also for embarrassing them.
"It's just been a really hard time going from having all of you guys to having nobody. I'm living in a house by myself, I want to pick up the phone and call my mom and dad. ... I'm just so ashamed that I publicly embarrass all of you. It kills me to the point that I feel like I can't make it up," Disick said as they all began crying.
"People are human and they make mistakes," Kris said, telling Disick none of them were worried about the perception of being embarrassed and that she never wants him to feel abandoned.
"I've never been this unhappy in my life, you know. It's just terrible. If I didn't have those kids, I would kill myself," Disick tearfully revealed. "But I have them and I'm going to be here and I'm going to make it right for them. I just hope that somehow … God can like, give me a chance or us a chance at this. It's weird to lose that many people that quick, you know."
"We all love you every much. It breaks my heart to see [Kourtney] in pain. It's one of the hardest things you can go through as a mom," Kris said to him, urging Disick to make the necessary changes in his life for the family. "You have to make the decision that what you want is to be a partner and a dad and involved and present and committed and you fight for what you want and you need and you love."
Finally, the conversation came to an end and Disick thanked them for their time and walked out – but of course, the door behind him remained open, leaving viewers wondering whether he would keep his promises this time around.
Keeping Up with the Kardashians airs Sunday (9 p.m. ET) on E!