At the Rose Ceremony in Los Angeles that followed the women's round of hometown dates, Arie chose to give roses to Kendall, Lauren Burnham and Becca Kufrin, sending Tia Booth back home to Weiner, Arkansas.
But Arie's decision ultimately came down to Kendall vs. Tia for the third spot in his Final 3.
"I stood there, looking out at them and truly didn't know what to do next. That's why I needed to pull Kendall," Arie wrote in his People blog of the conversation they had right before he handed out roses.
"My feelings for her were so strong, but I still had no idea if she was ready for marriage. My biggest fear was that at the end of this, I'd choose someone who wasn't ready or who didn't choose me back. At this point in the journey, Kendall was the embodiment of those fears."
Arie felt it was necessary to ask Kendall flat out whether she could envision herself accepting a proposal at the end of the process.
"In relationships, I believe in clear communication. I had to ask her, straight up, if she could see this working. When she sincerely answered yes, I knew I needed to see where our relationship would go," Arie revealed.
Kendall and Arie's relationship has been a slow burn on The Bachelorseason, as her first official one-on-one date with the pro racing driver wasn't until her hometown date in which he met her family in Los Angeles.
Arie was wondering if they could "make up for lost time" having "connected later than the rest" of his relationships with the other women.
"I can whole-heartedly say that I have never dated anyone like Kendall before. That's one of the great parts of being the Bachelor: you meet women who are so different from the people you usually date," Arie explained.
"Kendall is quirky, intelligent, fun, and definitely the only woman in the world who'd take me on a date to her taxidermy studio. This was actually an unexpectedly nice aspect of this leg -- taking a break from being in charge. Leading all the dates is really fun, but you can learn so much about someone by what date they choose and how they lead it."
Arie admitted that checking out a vast assortment of stuffed dead animals was interesting to say the least.
"Just like Kendall, the studio was surprising, weird, and wonderful. I think for the first 10 minutes I just walked around, mouth agape, saying 'that's so crazy' -- and that was before she showed me the rats," Arie recalled in his blog.
"It takes a really special woman to get me to re-enact scenes from our relationship with stuffed dead animals, but that's Kendall. She's sexy and fun, even when stuffing dead rats. Playing with our Arie and Kendall rats in front of the diorama of our first date in Paris was too weird and surprisingly fun."
Before Kendall introduced Arie to her parents, they had a chance to dive a little deeper into their relationship.
"Compared to the other remaining women, we had a bit of a late start... Because of this, it was important for me to tell her that I was falling for her. For me, our relationship had blossomed far beyond our extreme physical chemistry and into something more," Arie revealed in his blog.
"Walking into Kendall's house was totally surreal. Her screaming family, so excited to see her, was very cute."
Arie continued, however, "It was slightly less cute when they started grilling me, though. I understood and expected [twin sister] Kylie and [father] Bob's concerns about Kendall's readiness, as I had the same concern. One thing I did not expect was for Kylie to be a body language expert."
Kylie said she could sense a wedge or a gap between Arie and Kendall that day although it was apparent they liked and cared for each other.
"Honestly, I felt we were sitting farther apart because of the seating arrangement more than our emotional closeness. I knew I'd have to ask all the families for their blessing because this would be our one time to chat before a possible engagement," Arie explained.
Kendall's father Bob was hesitant to give Arie his blessing to propose, but by the end of the night, he said he'd support the couple of they decided to get engaged.
"At the end of a very fun but very stressful night, it felt great to hear that Kendall was falling for me too," Arie noted.
Arie said it was easy to question his connection with Kendall -- and whether they were far enough along to be a successful couple in the real world after the show -- but things became easier once they realized how good they made each other feel.
"Both of us grew so much from our relationship. She made me more open and fun, I made her more vulnerable and communicative. It was scary, but I was so excited to see where it could go," Arie explained.
In the nextThe Bachelor episode, Arie will enjoy an overnight Fantasy Suite date with his three remaining bachelorettes in Ica, Peru.