In PEOPLE's exclusive sneak peek at Monday's episode of ABC's retrospective series The Bachelor: The Greatest Seasons — Ever!, Randolph touches on their breakup, admitting that dating in the public eye took a toll on their relationship.
In the clip, host Chris Harrison asks Randolph what her relationship with Underwood was like when the show ended.
"It was really good. We honestly had a really great relationship the entire time, and we got along really well," she says. "Obviously, navigating a public relationship has its challenges."
Asked what ultimately led them to part ways, Randolph pauses before letting out a nervous laugh.
Morgan Lieberman/Getty Cassie Randolph and Colton Underwood
Underwood, 28, and Randolph, 25, announced their split in May after over a year together.
"Its [sic] been a crazy few months to say the least, 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 on Instagram at the time. "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."
Randolph captioned her post, "Colton and I have broken up, but have decided to remain a part of each others lives. With all that we have gone through, we have a special bond that will always be there. I love Colton very much and have an enormous amount of respect for him. We have both learned and grown so much these past couple years, and will always have each others back. Always."
At the time, a source told PEOPLE the breakup was "amicable," and that the two were determined to remain friends.
"It was a mutual breakup," said the source. "Colton and Cassie are still good friends, and they want to stay friends. It's definitely a priority for them. Colton is sad, but he's looking forward to what the future may bring."
In June, a source told PEOPLE that while the reality stars don't have any plans to get back together, Underwood and Randolph have seen each other "several times" since their breakup.
"Colton and Cassie are not back together, but they've been making a real effort to stay friends," said the source. "They've seen each other several times since Colton got back to L.A."
The Bachelor: The Greatest Seasons — Ever! airs Mondays (8 p.m. ET) on ABC.