Chris Randone and Krystal Nielson Slam JPJ's 'Scary' Fight With Derek at Their Wedding (Exclusive)

Randone wants an apology from John Paul Jones for his behavior.

Chris Randone and Krystal Nielson wanted their wedding to be perfect -- but it seems John Paul Jones got in the way. 

The fan-favorite Bachelor in Paradise star shows a side that fans haven't seen before in promos for Chris and Krystal's wedding, which will air on Tuesday night's episode of the Bachelor spinoff. JPJ is seen violently yelling in Derek Peth's face, for no good reason, according to the newlyweds. 

"Thankfully, this happened after the ceremony, right after they had a cocktail party," Chris explained during an interview with ET's Lauren Zima on Monday. "What you'll see is an argument and someone yelling and being very combative... there's nothing that would make sense for this argument to begin with." 

"[Derek] was attacked verbally, and it's unfortunate to say this, but JPJ was very out of line and aggressive," he added. 

Chris and Krystal were taking wedding photos during the altercation, but his mother saw the whole thing -- and was "scared." 

"He attacks Derek in a way where he seems very narcissistic and [has] a lot of anger, which scares and [makes people question], 'Who is JPJ?' as far as the emotional stability," Chris said, noting that he's upset by how JPJ chose to take away from the special day. 

"There's a time and place for those types of things, and the context of the conversation was completely out of line and inappropriate during a wedding. And that's why it's unfortunate that he releases these type of emotions and really lacking that self-awareness at a time where it's not about you. It's not about Derek. It's about her and I," he expressed. 

Chris and Krystal have nothing but good things to say about the "class and composure" of Derek, whom they had dinner with on Sunday night. They haven't spoken to John Paul Jones since the incident. 

"I just would like an apology to my wife," Chris revealed. 

Krystal, meanwhile, described JPJ's behavior as "aggressive." "It felt unwarranted and it felt like an ambush," she said. 

JPJ is seen in promos accusing Derek of essentially being a womanizer, which Wells Adams pointed out to ET on Tuesday morning is the opposite of how Derek has presented himself on Bachelor in Paradise thus far. 

"I was like, 'It doesn't make any sense to me'... If anything, he's a terrible dater and not a womanizer!" Wells argued of Derek, whom he said was dumped on JoJo Fletcher's season of The Bachelorette, dumped by ex-fiancee Taylor Nolan after their engagement on Bachelor in Paradise season four, and dumped by Demi Burnett earlier this season. 

"I think that's what sucks for John Paul Jones, is he's not able to see Derek's extremely respectful conversations with Demi," Wells noted. "There's no evidence to back up what you're saying. That's when you're like, 'Are you just coming unglued to come unglued?'"

JPJ and Derek's fight makes its way back to the beach on Paradise, where Wells said he got involved a little. It's their argument at the wedding, however, that Wells agrees was out of line. 

"What I thought about all that was that's a messed up place to have a fight. That's someone else's wedding. Know the room, and don't do it at a wedding," he shared. 

Bachelor in Paradise airs Mondays and Tuesdays at 8 p.m. ET/PT on ABC. Join ET's Bachelor Nation Facebook group here