"I didn't know why I felt so strongly, I just did," Arie wrote of the 25-year-old technology salesperson from Dallas, TX, in his People blog.
"I hadn't felt like this about someone since [former The Bachelorette star] Emily Maynard. This feeling was the reason I came back on the show."
Arie appears completely smitten with and invested in Lauren on The Bachelor. Despite a lack of easy-flowing conversation and the fact she struggles with being vulnerable, Arie has been waiting patiently for breakthrough moments with the bachelorette.
Arie has been criticized for putting his physical attraction to Lauren above all else, but he insists in his blog there was more to his fascination with this quiet and guarded woman than just her beauty.
"From the moment I met her, I knew I wanted to get to know Lauren more. In life, sometimes you're just pulled to certain people," Arie explained.
"The problem was, until our date in Paris, she was unable to open up. As attracted to her as I was, I needed more than just that gut feeling to be able to take her to a hometown. My hope was that in Lucca, we'd be able to build upon our amazing connection and the depth we reached in Paris."
In Italy, the pair rode bikes, walked and shopped, played soccer with some of the local children, and climbed a tower in the center of town.
"We had so much fun... The more I spent time with Lauren, the stronger I felt about her. At this point, though, I still had no idea how she felt about me. Yes, we had an amazing day... but I still had so many questions. Was she ready for a hometown? Was she falling for me too?" Arie wrote.
That night, Arie and Lauren enjoyed dinner at Villa Grabau, a historic estate outside of Lucca, and the pressure was on for Arie to seek the answers he needed.
"I hadn't been this nervous for a date in a long time. The stakes felt so high. Throughout the whole journey, I tried to think logically. I'd constantly ask myself: Do our lives fit together? Could she move to Scottsdale? Is she ready for marriage?" Arie revealed.
"With Lauren, it was never about those things. I couldn't logically explain any of my feelings."
Lauren finally gave Arie what he had been waiting for at dinner that night; she said she was falling in love with him and could envision a future with him.
While the typical Bachelor smiles and kisses a woman after a love proclamation, Arie did the exact opposite. He appeared shocked and maybe even concerned, and then he left Lauren alone at the dinner table to spend a minute by himself and gather his thoughts.
"I know excusing myself during dinner looks crazy. It felt crazy at the time, but when Lauren told me she was falling in love with me, I was overwhelmed," Arie confessed.
"In that moment, I knew I felt the same way but needed to take a moment before I could properly express myself."
Once Arie returned to the table, he told Lauren in Monday night's episode that he was "nervous as hell" because he felt some things for her that he hadn't felt in a really long time.
"If I was off or not myself and not put together," Arie told Lauren on their date, "it's because I feel vulnerable with you. And to hear you say you're falling for me makes me really, really happy. And I really do, really do, see something between us. I'm falling so deeply in love with you, it's crazy."
Arie was clearly being guided by his heart when it came to his relationship with Lauren on The Bachelor, which was a departure from his effort to think logically.
"Even if I couldn't quite explain why, I was falling in love with Lauren and needed to give her a rose," Arie noted. "Now, with two of the four hometowns decided, I felt more hopeful than ever."