Peter previously told ET there is a "specific reason" why he's confident no one is going to be able to spoil the details, which has left fans speculating Peter's love story is still playing out and the season's ending has yet to film.
"The crew is beside the point. Peter and I, going through this together, had no idea this was happening and how this was going to all come to an end," Chris shared.
"So, it's riveting, and it really is breathtaking and it'll break your heart."
During The Bachelor's three-hour premiere last week, ABC aired a preview for the dramatic and supposedly unpredictable ending of Peter's season.
"Before you do what you're about to do, there is something you should know," Chris told Peter in the trailer at what appeared to be the Final Rose Ceremony, which was filmed in November.
"There's something I just found out -- all of us just found out."
"Oh my God," Peter said in response, hanging his head low and rubbing his hand over his eyes.
"I'm not sure how all this ends, so I just wanted to give you a heads up," Chris added.
"I feel like I'm going to pass out right now," Peter said as he walked near his final rose resting on a stand. "This was just the last thing I needed to hear."
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Later in the preview for the season, Peter's mom Barbara Weber was shown crying to her son, "Don't let her go! Don't let her go. Bring her home to us."
The Bachelor franchise has witnessed many jaw-dropping endings in recent years.
Former The Bachelor star Colton Underwood jumped a fence to escape production and nearly quit Season 23 after the early winner of his heart, Cassie Randolph, threatened to go home because she wasn't ready to get engaged. (Colton and Cassie ended up together despite the odds and are still dating).
Lauren ultimately gave Arie another chance and then the couple got engaged onThe Bachelor: After the Final Rose. (They are currently married with one child, a baby girl).
Hannah Brown's recent season of The Bachelorette was also a shocker because she chose to call off her engagement to Jed Wyatt after finding out he had lied about the extent of a relationship he was in prior to appearing on the show's fifteenth season.
"[Peter's ending] is not comparable because it's completely unlike those stories the way it unfolds," Chris told ET.
"This will stand alone and be epic for a completely different reason."
Chris elaborated, "It's not for an athletic event or feat, and it's not for the topsy-turvy twists and turns that was Hannah. His is more of an emotional ride and roller coaster at the end."
Peter recently told ET his "unique" ending turned out to be "the hardest week" of his life; however, he has "no regrets" and is "very happy" that he followed his heart.
While The Bachelor leads typically hand out their final rose and propose marriage during the November finale tapings, it's possible Peter may be waiting to make a move during The Bachelor: After the Final Rose's live episode in March 2020.
"[Getting engaged] at the finale, at the [After Final Rose] -- that's a good guess," Peter had told ET. "You can't see this coming for a mile, so maybe. I don't know."
The Bachelor's 24th season will continue airing on Monday nights at 8PM ET/PT on ABC.
To read spoilers on how the rest of Peter's The Bachelor season unfolds, his Final 2 bachelorettes and more, click here.