'Married at First Sight' Reunion: Justin and Nate Clash Before Justin Makes a Shocking Allegation (Exclusive)

ET has an exclusive look at part one of the explosive 'Married at First Sight' season 15 reunion.

Things are getting heated on the Married at First Sight reunion couch. In this exclusive look from part one of the season 15 Married at First Sight reunion, tensions between Nate and Josh reach an all-time high after host and ET's own Kevin Frazier asks if anyone on the cast has blocked each other on social media.

"I didn't block anybody, he basically unfollowed a good amount of people," Nate shared.

"I unfollowed everybody," Justin revealed, before sharing his reason for blocking Nate. "I blocked you because you're two different people."

He continued, "Sometimes you're one way, sometimes you're another and that's just not my cup of tea, so for me, I'm just like, 'Ahh.'"

When Nate asked what Justin meant by that, he put it pretty plainly stating, "Fake. You're fake."

Nate then asked for an example, but Justin didn't think one was necessary. "I don't need to give you an example, it's too much to go through," Justin said.

"'Cause you can't really come up with anything," Nate shot back.

Pushed by Nate, Justin then shared an anecdote from the season, in which he claimed that Nate was not there for him throughout their time on the show.

"First, when I came to you when we were living at the community, we made this bond like, 'Hey, we're gonna be there for each other throughout this experience,' but what'd you say? 'My dad raised me a certain way, I don't get in people's business.'"

"But when Morgan was explaining herself at Binh's place, you was all in Binh's business," he continued, with the camera panning to Morgan who seemed to agree with Justin's claims.

"I was like 'Oh, OK, so you pick and choose," Justin added. "I was like alright. You act one way with other people, you act another. You're fake. It's OK."

Nate then took the moment to share his side, telling Justin that didn't want to be in a position to be anyone's "therapist."

"If you come to me, I'll talk to you, but I'm not going to be tending to you because you're not my wife," Nate said. "I have to focus on my wife. So, for you to get upset because I'm not paying attention to you, is weird."

"That's not weird," Justin shot back.

"It is weird, and you a crybaby," Nate said.

The back and forth continued, with Nate calling Justin "emotional" for unfollowing him, but Justin wasn't done either, making a shocking allegation that left the rest of the cast, and Frazier, stunned.

"Bro, you made a pass at me twice before the show," Justin alleged.

See Nate's response when part one of the Married at First Sight reunion airs Wednesday at 8/7c on Lifetime.

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