The rivalry between The Bachelorette season 11 contestants Shawn Booth and Nick Viall is going to intensify in episode 9.

A new promo of the 6 July episode shows Kaitlyn coming clean and revealing to Shawn that she slept with Nick.

According to an E!online report, Shawn is so "distraught" over the revelation that he interrupts the rose ceremony, not because she slept with someone else, but because it was Nick she slept with.

"Shawn just couldn't get over it. He was obsessed," a source told the website. "He was more upset that it was Nick than anything else. He asked Kaitlyn, 'Why him?' He didn't understand why, out of all the guys, it was Nick she had to sleep with."

Shawn has already made it very clear how much he dislikes Nick on the show, mostly referring to him as "the other guy," and their rivalry is going to reach breaking point in the upcoming episode.

"Nick felt he had tried to get to know him and was rebuffed at every turn," the insider shared. "He didn't have any respect for the way Shawn was handling himself. Shawn never gave him a chance."

The two men are unlikely to bury the hatchet anytime soon. "Nick and Shawn never end up making peace on the show. It's one of the most bitter rivalries the franchise has ever seen," the source revealed.

The Bachelorette's Kaitlyn Bristowe blogged about her feelings for Nick and Shawn, saying it is not possible to date all these different men without upsetting anyone.

Bristowe wrote, "It's not possible to date all these different men without upsetting anyone. When Shawn asked me point-blank if I was in love with him, I was surprised. Again I found myself sitting there asking was it fair to say yes? Was it unfair to say yes? I could understand his perspective – it wouldn't have made sense for me to be in love and having intimate relationships with other people when I cared for him. Yet that's what was happening.

"When Shawn interrupted my interview, I didn't know what to think. I was preparing myself for the worst. I thought he was coming up to tell me he was leaving, which I feared. I thought maybe Nick had said something to him. I didn't want him to hear about what had happened between Nick and me from anyone else but me, and I just wanted the timing to be right for me to tell him myself," she said.

Are you Team Nick or Team Shawn? The Bachelorette airs on Mondays at 8pm on ABC.