Andy then uncovered the real story behind Jax's infidelity before former BFFs Scheana and Lala Kent got into it. Jax also opened up about the passing of his father, which later fueled his explosive argument with Scheana.
We all know that Jax cheated on Brittany with Faith, but we didn't know the gory details -- until now.
"Jax, Faith told James [Kennedy] that you hooked up with her in front of an ailing 95-year-old woman," Andy said, to which Jax replied, "I didn't see that."
"You didn't see that? You were in an elderly woman's home that she was taking care of?" Andy said, to which Jax replied, "I guess, yeah."
Jax asserted he "did not know anything about the elderly woman" even though the home Faith had invited him to "did look like an old woman's house."
"I feel so bad for that woman," Brittany interrupted. "I feel so bad for whoever hired that horrible person that would do that to an old lady."
Jax repeated to Andy what he's been saying for months -- that he's sorry, that Brittany's the best thing that's ever happened to him and that he's truly a changed man.
"Instead of being an adult and actually getting help and trying to figure out why I do these things, I take the coward way out," Jax said, fighting back tears. "And I hate to say this -- and it sounds disgusting and trashy -- but it could've been anybody that walked by. That's just the person that was paying attention to me at the time. It really didn't matter. It could've been a damn hole in the wall."
Lala made her big return to "Vanderpump Rules" after Scheana reached out and convinced her to give the group and her job at SUR another shot, but after watching back the season, Scheana had a bone to pick with Lala, saying she felt "shit on" after seeing Lala's interview bites.
"You kind of did a lot this season from what I've seen," Scheana said. "Your interview bites are mean. I mean, the tone deaf thing was rude. You were the one who said you wanted this."
"I didn't make you sing!" Lala fired back. "I didn't sit there and hold a gun to your head and say, 'You better get in there and sing!' And then you blame your tone deafness on my lyrics?"
But Lala offered Scheana a very reasonable explanation as to why she spoke poorly of her during her interviews: "You don't know how to talk about anything else besides you, you, you, you. And I'm over it. I have gone through many months of hearing just about Scheana."
Tom Sandoval had the same bone to pick and informed Lala he didn't appreciate when she said his trumpet playing sounded like "baby dolphins just learning to communicate for the first time." (But c'mon, Tom, that's just plain funny.)
Lala later said she felt Scheana stopped reaching out to her when the latter moved to Las Vegas. Scheana then shamed Lala for not invited her to fly out to Vegas on her man's private jet.
Stassi said "it was horrifying to watch" the demise of her relationship with her condescending POS boyfriend, Patrick, and added that she felt "stupid" for dating him for as long as she did.
Ariana Madix -- who's usually never on Team Stassi -- told Stassi, "Don't feel stupid. We all watched him and thought he was disgusting, so don't feel stupid. You look amazing; he looks disgusting."
Ariana said she felt a connection with Stassi because she, too, was submissive in her last relationship.
"There are similarities, but I think my ex went for the jugular a lot more often than Patrick probably did," Ariana explained. "When I watch her and I see that she's nervous that he's gonna disapprove of what she's saying or doing or who she's hanging out with or whatever, I lived with that constantly... I'm glad that you're out of that. I'm glad that I'm out of that."
Stassi said she's learned a lot and is happy with her new man.
Jax's dad passed away from cancer on December 27, 2017 -- after the season wrapped and before the reunion was filmed. At Andy's mere mention of his dad, Jax broke down completely.
"He was my best friend," Jax said tearfully. "I talked to him every day. Even though he lived in Florida, I'd just text him, even about anything."
Jax said he had just FaceTimed his dad on Christmas Day and was getting ready to go visit him, but then his mom called.
"We were actually on the way to dinner, and I had the phone plugged in," Jax said, blubbering. "My mom's on the phone screaming, 'Your father's dead.' And then I stopped the car and just collapsed and she took over. Ever since then, I can't imagine myself without her."
Jax had two funerals for his father: one in Florida and one in Michigan. He said Tom Sandoval and Tom Schwartz flew out to the Florida wake, and that Stassi, Kristen Doute and another woman Jax dated -- Rachel -- all flew out to the Michigan wake.
"It says a lot about the people they are considering my past with all of them," Jax said. "It was just amazing."
Jax said his father's funeral was his "first funeral" and the first death he's ever had to face.
Scheana embarrassingly doted on Rob all season long. She even told Lisa she thought about Rob on her wedding day -- when she married Michael Shay.
Scheana then went into a long story about how she and Rob met. As her cast mates began to glaze over, Lisa interrupted, "Can we do the short version of this?"
Toward the beginning of the season, it was brought to Scheana's attention that Rob kissed another girl, a "rumor" she refused to believe.
"That was the moment he pulled away," Scheana admitted to Andy. "And I never, ever, ever meant to discredit Shay because he was f-cking amazing. And the thing about Shay was he had my back for all five seasons, even when he felt I threw him under the bus and put his addiction out there -- he never left me because of the show. And for Rob to just so quickly shut off from me..."
Scheana said Rob broke up with her "about two weeks" after Season 6 wrapped and that he didn't do it while the show was being filmed so that she wouldn't have to have another breakup storyline.
When Jax said Rob had been texting him "to go and hang out and drink," Scheana lost it.
"I was head-over-heels in love with him," she said tearfully. "I was for a really long time, and it didn't work out. I have loved Rob for 12 years, and he broke my f-cking heart. For the first time, that genuinely broke me."
Scheana felt Jax was trying to sabotage her relationship, so she made it her mission to sabotage his. Many a times this season, she would say Jax was jealous of Rob, so Andy asked Jax what he thought of that claim.
"OK, cool. That's great. How'd that work out for you?" Jax said sarcastically.
"F-ck you, Jax!" a tearful Scheana fired back. "F-ck you for saying that!"
"You didn't even call me when my father died!" Jax yelled back.
As Scheana got up to excuse herself from the group, Jax continued to take digs.
"I had two ex-girlfriends and a girl who hated me show up in Michigan without even asking, and you can't even give me a f-cking phone call?! F-ck you!" he said. "You can't even keep a boyfriend for more than 5 minutes!"
Cameras followed Scheana as she walked back to her dressing room to get her makeup touched up. "Why is this, like, harder than my divorce?" she said sobbing.
Part 2 of the "Vanderpump Rules" Season 6 reunion continues Monday, May 14 at 9 p.m. on Bravo.