In his book, The First Time: Finding Myself and Looking for Love on Reality TV, the former Bachelor revealed that he and Randolph briefly broke up after the show. Their split in August of last year only lasted a couple of days, but as Underwood told ET's Lauren Zima back in March, it was enough to teach him that there's "no certainty" in their relationship.
"There is no certainty right now. I mean we're not engaged, we're not married. I love her to bits and pieces and I think that for us, we just need to keep communicating and having those open conversations with one another," he said. "I mean, we're just taking it day by day right now."
However, the pair announced on Friday that they were calling it quits once again, sharing statements on social media that reinforced their friendship and plans to continue to be in each other's lives.
"Cass and I have been doing a lot of self-reflecting. Sometimes people are just meant to be friends - and that’s okay," Underwood wrote. "We both have grown immensely and been through so much together - so this isn’t the end of our story, it’s the start of a whole new chapter for us."
The former Bachelor said in The First Time that he and Randolph were hoping to see an engagement happen this year -- and while he told ET he was grateful to have her support amid his coronavirus recovery, it hadn't made him want to propose. After his COVID-19 diagnosis, Underwood had been self-isolating on the third floor of the Randolph family home in Huntington Beach, California, but noted they the couple didn't experience the same quarantine-induced time together that other couples have.
"It's still a day-by-day thing at this point," he repeated of his relationship with Randolph. "There is not certainty right now in this world."
Underwood's lax attitude was seemingly a direct response to the issues that caused his initial breakup with Randolph last year.
"I put a lot of pressure on our relationship when I was always defending it or I was overcompensating and trying too hard. I was almost pushing her away by trying to bring her closer," he explained. "I was saying, 'No, we'll be fine. We'll be engaged by this date. We'll do this, we'll do this, we'll do this.' And it was sort of overwhelming her all over again. "
"[I said things] like, 'We need to talk about this. You can't just, like, go out in the media and say this,' or 'You can't just tweet about this or Instagram like this without communicating and talking with me,'" Underwood recalled. "We both just let a lot of things -- little things -- build up, because we got busy."
Micromanaging their relationship wasn't working -- but neither was the lack of communication. "She was doing a lot of things on her own and I was doing things on my own and we forgot what made us so strong together was that communication and working through problems together... being there for one another and being a team," he said.
Underwood and Randolph celebrated their one-year anniversary last November, and he told ET in March that they were in the process of making some important decisions -- just without a specific timeline attached.
"We decided that we're not moving in together until we're married. So, we have that to look forward to in the next step into our relationship," he revealed. "But as far as like, timeline, we still talk about her finishing school and this and that."
The pair also discussed having kids together, with Underwood joking that fans won't find out if he lost his virginity until Randolph's possible future pregnancy announcement. "You sort of get a two-for-one when we decide to have kids," he cracked.
The former football player's new book, The First Time, addresses his relationship with Randolph, his sexuality, his virginity and more -- and he said he hopes it will help readers work through some of their own issues.
"There's a lot of little things in there that I feel like can help a lot of people," Underwood said, before thanking his friends, family and Bachelor Nation for making the book possible. "Whether you liked me or didn't like me in those three seasons [on Bachelor shows], thanks for being there with me and going on that ride with me. And thanks to the show. I have mixed reviews when it comes to [my time with the franchise], but at the end of the day, I'm very happy and very in love with Cassie and I have them to thank for that. So, I just wanna say a big thank you."
The First Time: Finding Myself and Looking for Love on Reality TV is now available where books are sold.