Blake Moynes Reacts to Ex Katie Thurston Moving on with John Hersey, Talks 'Emotional Cheating'

Blake Moynes was blindsided by Katie Thurston's new relationship.

The Bachelorette winner, who split from Thurston a month ago, has broken his silence on her "12 Days of Messy" Instagram series, in which she revealed on Tuesday that she'd started a romantic relationship with John Hersey, another contestant from her season.

"You start to think about timelines. I know they spent a lot of time together and stuff, but there's just no way, I didn't have an inkling," Moynes, 30, said on Wednesday's episode of the Talking It Out with Bachelor Nation podcast. "I'm a very secure guy, a confident guy, and I give my trust out 100 percent, especially to the person I should be trusting the most."

He continued: "I really don't think there was any physical cheating there, but there's clearly emotional for it to transition as quickly as it did."

"I feel stupid and foolish for allowing it to happen, to some degree," Moynes went on. "And I don't know if it was partially me too, like, was she in some sense emotionally cheating because I wasn't able to provide something with words of affirmation, which I know I struggle with sometimes?"

Thurston, 30, announced her relationship with Hersey, 27, on the final day of an Instagram series she titled the "12 Days of Messy." Each day, she chose a song from Taylor Swift's Red (Taylor's Version) album that reminded her of a man from her season. Moynes was Day 1 with "We Are Never Getting Back Together," and Hersey was Day 12 with "Begin Again."

"It's known Katie and John became close friends post-season," her rep told PEOPLE after Thurston's post on Tuesday. "John has been there for her through all the major changes in her life and they are excited to explore this newly found romantic connection."

Hersey posted a TikTok of the couple holding each other and kissing on Tuesday, too. The news came after the pair had been sharing glimpses into their friendship post-show, including while Thurston was engaged to Moynes.

Moynes said on Talking It Out that he's struggling to figure out the timeline of Thurston's connection with Hersey. "That's what I have a hard time processing, I think, just because this 12 Days of Messy — that I didn't sign up for but I was attached to like all the other guys — it started 12 days ago."

"I'm sure she probably knew who day 12 was — who it was going to be and why," he continued. "So when I try to think about the breakup happening when it did, roughly a month ago, she probably had an idea two weeks after that who was gonna be day 12 and how she was gonna announce it."

As for whether he has regrets about his relationship with Thurston? "I try to stand by having no regrets, but it's instances like this where you start to fight yourself with having no regrets," he admitted.

Thurston and Moynes announced their split in a joint statement posted on social media on Oct. 25. (Thurston has since deleted the post from her Instagram feed.)

"It is with mutual love and respect that we have decided to go our separate ways. We are so grateful for the moments we shared together and the entire journey that has unfolded this year, but we ultimately have concluded that we are not compatible as life partners, and it is the most caring choice for both of us to move forward independently," they said. "We ask for kindness and privacy as we both navigate this transition. Both of us will forever want the best for one another and ask you to please support us in our decision."