As tradition dictates, the couple sat down with Jimmy Kimmel following the finale, and they put their relationship to the test by playing The Newly Engaged Game -- based on the popular Newlywed Game.
Viall and Grimaldi competed for some fun, must-have household accessories -- like a cherry pitter, a turkey baster and a panini press -- by correctly answering trivia questions about the other. For example, Viall knew that Grimaldi is a Libra, while she knew that his middle name was Joseph. Really, the bare minimum an engaged couple should probably know about one another.
The game also got Grimaldi to reveal who her celebrity crush is, and most people wouldn't have ever guessed it: retired NBA pro Rick Fox.
"That’s a weird one," Kimmel quipped after Viall correctly answered the question.
For the grand prize -- a set of Bachelor and Bachelorette fine china -- they pair had to answer the most personal question of the game: Where was the first place they made love? As it turns out, the couple first hooked up in Finland, where Viall popped the question.
While the pair might know each other pretty well, there are still a few puzzles they're going to have to solve -- like where they are going to live.
Speaking with Kimmel before they played the game, Viall and Grimaldi admitted that they haven't worked out a permanent living situation, given that Grimaldi is a Canadian citizen who lives in Montreal while Viall resides in Los Angeles.
"She’s Canadian so we have to figure that stuff out," Viall said. "She’s gonna be spending as much time as possible out in L.A., where I am currently living."
They pair also said they haven't started thinking about wedding plans just yet, and are taking "baby steps" in their burgeoning relationship.
"We haven’t even had a dinner reservation yet," Viall said, referring to the secrecy the couple had to maintain between their engagement and the Bachelor season finale. "So we’re going to do that first."
However, Viall is going to be busy with yet another reality show in the coming months as he competes on Season 24 of Dancing With the Stars, alongside his pro partner Peta Murgatroyd. Or, as Kimmel put it, Grimaldi gets to go from "watching Nick make out with other women on The Bachelor to… dancing with this beautiful Russian supermodel dancer."
"She's happily engaged," Viall said of Murgatroyd, who recently welcomed a baby boy with her fiancé and fellow DWTS pro, Maksim Chmerkovskiy.
"Guaranteed that’s why they paired her with you," Kimmel joked.
And Grimaldi couldn't be more supportive of her fiancé's participation in the show, telling Kimmel, "I was really excited about the whole DWTS experience. He ran it by me, we spoke about it."
"Peta's a great dancer," she added. "I'm really happy that he got to be paired up with Peta so hopefully [he'll] make it to the end."
For more on Viall and Grimaldi's romantic engagement on the season 21 finale of The Bachelor, check out the video below.