"Choosing Rachel for my one-on-one this week was easy. From the very first night we'd had an instant connection and chemistry," Viall wrote in his People blog.
"Over the past few weeks, I felt like we had built something special and this was a date that I felt could really push our relationship forward."
Viall said the day was all about exploring New Orleans together, something a real couple might do outside of The Bachelor world.
"Of course, helicopters and yachts are romantic and unbelievable experiences -- but there is something about just walking through a city with no real plan that makes a bond so much greater. It was also pretty cool that Rachel had just been to New Orleans, so she was giving me the inside scoop on these new experiences for me," Viall revealed.
"From eating the most delicious beignets to dancing in the streets and listening to some amazing live music, my date with Rachel couldn't have been more fun."
Viall also let fans in on a scene that wasn't shown in Monday night's episode. The couple saw a show by Lolo, an artist whom the Bachelor said had "an unbelievable voice and stage presence."
"Not to brag, but I think Rachel and I tore up that dance floor and Lolo loved us! But with Rachel on my arm, who wouldn't? Am I right?" Viall noted. "But honestly, I ended up downloading a bunch of Lolo's music later that day and playing it for Rachel that night as a surprise."
As delicious as the treats were and cool as Lolo was, Viall said the second line of dancers, singers and musicians was "by far the coolest part" of their day because they felt welcome "in such a joyous way." Viall and Lindsay found the community's energy "intoxicating."
"I remember feeling such a high this day and reflecting on my decision to give her the First Impression Rose the night we met. I was reminded of how confident I felt about her then, but on this day, also so confident in what was to come. The energy of our day carried into the evening," Viall wrote.
"The location where we had dinner was so cool, I wish you guys could have seen more of it. This place is the home to hundreds of Mardi Gras floats that range from traditional to absolute insane. We started the evening off running around like kids playing hide and seek, and stealing a few kisses in private away from the eyes of the floats."
As shown in the episode, Lindsay opened up at dinner about how she had just visited New Orleans for a funeral.
"It was really moving when Rachel opened up about the reason she had just visited New Orleans not that long ago. It is tragic to lose someone close, but having that reminder to take advantage of every opportunity that life gives you," Viall said.
"Rachel is someone who in the past, had expressed how it was hard for her to open up, but that evening we connected more than we ever had before."
Viall flat out admitted to Lindsay on their date, "I might be breaking the rules here, but I'm super into you."
"I couldn't help but feel this desire to let Rachel know just how excited I was about our relationship," Viall continued in the blog. "I was crazy about her! Moments like this can be few and far between and I didn't want to waste the momentum that we had."
Viall then took an opportunity to gush about the bachelorette, a 31-year-old attorney from Dallas, in his blog.
"Rachel has a way of allowing herself to be vulnerable without losing confidence or questioning herself," Viall insisted.
"By the time our evening ended, I had almost forgotten that there was a rose on the table, but there was no doubt that I was giving it to her, and there was no doubt that I was starting to feel like this relationship had a big future."