"Everything's about to turn onto its head," Jesse toldEntertainment Tonight of what's to come on Zach's season.
"We're going to be involved in a situation that I don't think we've ever had on the show before."
Jesse said Fantasy Suites simply didn't go as Zach had anticipated or hoped.
"This is not what Zach had planned and he is going to have to dig deep to try to pull himself out of this," Jesse said.
"This is going to be more dramatic and more emotional by leaps and bounds versus anything that we've seen this year."
In a separate interview withUs Weekly, Jesse explained how Zach's approach to overnight dates wasn't realistic, even though The Bachelor star had thought it would help him make his decision at the end.
"So Zach decides that he is not going to sleep with any of the three women, that he's going focus on other means and ways of progressing his relationships, but things don't exactly go that way," Jesse shared with the magazine.
Jesse, who starred on The Bachelor's fifth season in 2004, noted that "sometimes you can't put boundaries" on relationships in The Bachelor franchise because they need to "progress" organically.
FOLLOW REALITY TV WORLD ON THE ALL-NEW GOOGLE NEWS!
Reality TV World is now available on the all-new Google News app and website. Click here to visit our Google News page, and then click FOLLOW to add us as a news source!
Jesse assumed Zach was going to be "tempted" behind closed doors, and the host pointed out how Fantasy Suites exist "for a reason."
Jesse said he believes "sexual compatibility is a really big thing" in a romance, "especially if you're going to be getting down on a knee and asking someone to marry you."
When elaborating on why Zach's initial plan to stick to conversation during overnight dates would be problematic, Jesse said, "What if the women want to have sex with you?"
"You're kind of taking it off the table," Jesse explained. "That was probably the most shocking [moment] because in all honesty, part of me kind of knew how it was going to end."
Jesse teased of Zach's final weeks of his The Bachelor journey, "Zach, we know is extremely thoughtful. He has a very heavy conscience. So he's going to have to navigate a lot in these final few weeks, and he hopefully won't ruin it for himself."
"I think Bachelor Nation is going to be absolutely thrilled at the outcome. I don't want to speak on behalf of Zach. It was a very difficult journey to get to this point. Everybody up to this point has seen that," Jesse said.
In a preview for Fantasy Suites that aired at the end of The Bachelor's March 13 broadcast, Zach says, "I think to a lot of people, this week is viewed as 'sex week.'"
"What feels right to me is not having sex," Zach adds.
But then Ariel says, "Zach is looking delicious today," and Gabi and Zach are shown kissing in bed.
Kaity also kisses Zach and boasts, "It feels so right with him."
Jesse teases that what happens on the overnight dates "will change everything," and Zach reveals, "Something really special happened. I feel like I let myself down, and I feel like I let the women down."
Zach goes on to reveal, seemingly to Gabi, "I have been intimate this week."
Gabi then cries, "I feel so stupid. I feel disgusting. I feel ugly. Heartbreak doesn't feel good, but this doesn't feel good either!"
After Zach appears to apologize to Ariel, Gabi proceeds to tell the cameras, "I don't even feel like I can go back there."
An unidentified woman could then be heard saying she's "confused" and "really [wants] to go home."
And Zach laments to Jesse, "I really f-cked it up. It was a beautiful moment. It feels robbed."