Here's the moment that really got him.
"What I wasn’t expecting to see is my father Chris and Vanessa crying in each other’s arms," he writes. "I think his message of needing to push beyond the feelings of love and embrace the sacrifices couples have to make actually turned out to be some of the best advice we got on our relationship. Vanessa made her struggle with not getting the well-defined answers crystal clear weeks before, and I could tell she was second guessing everything she felt. I’ve been in her spot. Having the old man explain to her that sometimes letting go of something is the only way to hold onto the people you love may have saved us."
So, a moment of well-timed weakness was what ultimately swayed him. That's certainly understandable, Nick was clear that he was experiencing emotional swings just as violent as his suitors' throughout the season.
Viall also captured another adorable moment that made him love Vanessa.
"It was so cute to see her jump on that horse like a Canadian Mountie," Viall writes. "Out of all the stunning settings I had gotten to share with these women around Finland, riding up that mountain on horseback was the most beautiful. I tried to describe it but the only word that came out of my mouth was 'wow.' It’s a place on Earth you have to see to truly appreciate."
Apparently all you need is the love of your father and the most beautiful frostscape on earth to win Nick Viall's heart.