As shown on Monday night's episode of The Bachelor, Dorfman surprised Viall with a visit to his hotel room in New York.
She had dumped Viall -- who had already picked out an engagement ring for her -- onThe Bachelorette's tenth season in favor of Murray, who popped the question at the final Rose Ceremony in the 2014 finale.
So fans are wondering why Dorfman wanted to talk to Viall on his The Bachelor season and whether she was hoping for a reconciliation.
"I think they're perfect for each other, to be honest," Murray, 32, toldEntertainment Tonight when the topic of Viall and Dorfman's reunion on the show came up. "Knowing both of the people and who they are, they should have ended up together."
Murray never seemed to like Viall, especially since the current Bachelor star revealed on After the Final Rose several years ago that he had sex with Dorfman in the Fantasy Suite. The public announcement left Dorfman embarrassed and she called it "below the belt."
Viall and Murray also have history -- an on-screen rival -- on Season 3 of Bachelor in Paradise. Viall briefly dated Amanda Stanton until Murray showed up in Mexico and stole her away and ultimately won her heart.
When asked whether he thinks Viall's relationship with his final pick will last after Season 21 wraps airing, Murray admitted the Bachelor tends to be "very pessimistic when it comes to what I feel like the intentions are at the end."
"I feel like I know Nick pretty well, and I wish the girls luck for sure," Murray added of the 36-year-old former software salesman.
Murray and Dorfman, 29, called off their engagement and split in January 2015 after eight months together.
About a year later, Dorfman released a tell-all memoir It's Not Okay in which she revealed personal details about her romances with both Viall and Murray. She detailed an awkward sexual encounter with Viall in the Fantasy Suite and accused Murray of being controlling, temperamental and verbally abusive in their relationship post-show.
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"That's Andi's way of making money and stuff, and that's great, and if I've got to be the fall guy for everything in whatever her stories are, then whatever," Murray told ET of the memoir, adding that he has "no intentions of ever seeing or talking" to Dorfman again.
And Bachelor Nation shouldn't expect Murray to pen a book of his own any time soon, although he's been approached about the opportunity.
"It's very tempting to tell the truth," he said, revealing he doesn't want to attack people. "There could be a book written that would be very, very bad, but that's not something I want to do."