Nick Viall has revealed the most difficult part of The Bachelor process having appeared on the reality franchise four times.

The Season 21 The Bachelor star opened up about why a handful of women, including Vanessa Grimaldi and Rachel Lindsay, got so upset during the latest episode's group date in St. Thomas when it was supposed to be a fun day in the sun of volleyball and cocktails.

"Easily the hardest two weeks of that process is the two weeks before hometowns," Viall said during an appearance on Bustle's Bachelor podcast, Will You Accept This Podcast, "because everyone left is so emotionally invested at that point and you're still living with your peers."

Viall certainly lived a day in these women's shoes, as he had competed for both Andi Dorfman and Kaitlyn Bristowe on two separate seasons of The Bachelorette. Viall finished as the runner-up both times, having survived the hometown and Fantasy Suite dates.

"It's a nightmare feeling," Viall said. "Early on, it's like... This is great, I barely know this guy. These girls seem nice. Group dates are weird, but whatever... Then days feel like weeks and weeks feel like months."

Viall explained that when you're cut off from technology and have nothing to do but think about the person you're dating, naturally you go a little stir crazy and probably get emotional.

"You're trying to process a feeling that you know is wrong, you know is not normal, but you feel you have to accept things you shouldn't otherwise accept," Viall elaborated.

"We're only human and it's truly just a nightmare to try to manage those feelings within that world... It affected the women and it affected me. And that's pretty much what you saw. Every point and moment is precious."

In addition to Grimaldi and Lindsay, Corinne Olympios, Jasmine Goode, and Danielle Maltby were also on that group date in St. Thomas. Most of the girls were growing impatient because they wanted more alone time with the Bachelor or frustrated because he focused his attention on the season's villain, Olympios.

Maltby accused Viall of ignoring some of his bachelorettes to validate Olympios' drunken antics on the beach. Lindsay admitted she no longer felt like one of Viall's "top picks." Grimaldi complained gossip was "so annoying" and she was getting tired of competing for Viall's time.

And last but not least, Goode lost her cool over the fact Viall had yet to take her one a one-on-one date, or even just a two-on-one date. That night, Goode jokingly threatened to choke the Bachelor on numerous occasions, but Viall didn't find it funny.