Bachelor in Paradise's September 6 episode appeared to catch Brendan using Natasha as a placeholder, waiting for Pieper -- whom he apparently dated for about two months "without labels" before Season 7 of the spin off began filming -- to arrive in Paradise.
"Honestly, the disregard for a human [was the worst part]," Natasha, 33, toldEntertainment Tonight. "The disregard for me."
Brendan, while covering his microphone on the beach, admitted to "incriminating" himself by essentially admitting to Pieper he had downplayed their pre-Paradise romance to other cast members and had to do "certain things" in the Paradise process to ensure they could reunite on the beach.
Natasha, who developed strong feelings for Brendan along the way, called the bachelor "a liar" and clout-chaser considering Brendan had insisted he and Pieper just had a "super casual" fling back home and had only hung out twice -- when, in reality, he and Pieper had enjoyed about 10 dates.
"He literally told her, 'I had to do things and navigate things in a way to stay here.' And clearly, I was the casualty," Natasha explained to ET.
"There was never a, 'Well, how do you think Natasha feels?' and 'Well, what about Natasha?'"
The yoga instructor added, "That was the most shocking, awful thing, in my opinion."
Natasha said her intention with Brendan was to hopefully form "a meaningful connection," even though the romance and physical aspects of their relationship were coming along slowly.
"It was like, okay, we have this emotional connection that I felt that I thought he felt as well," Natasha explained.
"There were just things that I could feel that he was holding back. I just thought that that was because he wanted to take things slow... and I really didn't think that he was waiting for Pieper. That was stupid on my part."
Natasha went on to complain of the 31-year-old commercial roofer, "He's making a mockery of what this can be... He just seems like a very selfish person. And that's my biggest takeaway from who he is: selfish."
Natasha also apparently disagreed with Brendan's perspective she had "zero other prospects" in Paradise at the time they were dating, which was part of Brendan's justification for exchanging roses with Natasha -- despite allegedly lacking a spark -- up to the point of Pieper's Paradise entrance.
"I got his rose the first week, the women had the rose the second week, men would've come to talk to me," Natasha insisted.
"But also, I would've been fine going home if I wasn't creating this authentic connection with someone. That's what I was truly there for... If I would've went home, because there was no one there for me, that would've been okay with me. I would've went on with my life and not felt so betrayed, to be honest. And lied to."
In addition, Natasha said she was "surprised" to hear Brendan and Pieper openly discuss, while wearing microphones, their influencer status and how many Instagram followers they had prior to the start of filming.
Brendan was also caught calling Natasha "annoying" during a private conversation with Pieper.
"I was very surprised, because for me, it was so much more than that [follower counts]," she noted.
"I had been nothing but so sweet to this man. All the little conversations that him and I have had about life, about love, about our families, all the deep things that we talked about, was just for followers? Was just to wait for this person to come?"
Natasha said that while talking to Brendan "felt very empty," she had no idea his guarded behavior was because of feelings he still had for Pieper.
Since the footage aired of Brendan betraying Natasha, he has lost more than 100,000 followers and Pieper's follower count is down about 9,000. As for Natasha, she has gained nearly 400,000 followers, ET reported.
"At first I was like, 'I didn't want any of this. I didn't want this to happen. I didn't want these events to happen the way that it did,'" Natasha recalled of when she first learned Brendan and Pieper's follower counts had plummeted.
"I didn't initially feel the validation on the beach from other people, because they just didn't know all the things that were happening, but for everyone watching... to really feel how I felt when everything transpired, and they really stood behind me, I was like, 'Wow, this is insane.' I'd never seen anything like it before. I couldn't believe it."
Natasha said it's "a hard pill to swallow," thinking about how all the things she had said to Brendan allegedly "meant nothing" to him.
Brendan just released a lengthy seven-minute video apology Thursday on his Instagram account and said he and Pieper were never in an exclusive relationship.
"I saw his apology on his page, and the numerous attempts that she has said for press, and all these different things. It's like, 'Guys, hi. Again, the person who you're disregarding. Call me, text me, DM me.' They don't care about me," Natasha said.
"This happened in June. If they cared anything about me, they would've reached out before. I know that now. Again, it's a hard pill to swallow, because I cared about him a lot."
"It sucks when you're a super trusting person, you can't fathom people being this way, and being dishonest," she added in her interview with ET. "This is what it seems like to me. 'I'm losing followers, I'm losing this, I'm losing that. I should say something now.'"
Natasha, however, has confirmed she doesn't "wish hate" on either individual and is not a "vengeful" person.
"I just know that you have to keep toxic people out of your life. Once I realized how toxic he was... [I decided not to] engage. That's how I deal with it," Natasha explained.
"If they would've just posted a picture together, like, 'Hey, I know this episode sucked. We're sorry, but we are in love, and we love each other, and we wish Natasha the best.' Boom. I would've been right there. Like, 'Go ahead, y'all.'"
But instead, Natasha accused Brendan of "feeding into the villain role," like when he posted a picture of himself in a pool last week and joked about how he was onBachelor in Paradise "for the wrong reasons."
Pieper also joked about rumors being true regarding her pre-show relationship with Pieper in a playful TikTok video and wrote on her Instagram account, "All's fair in love and war."
"Y'all really don't care that I was the casualty in this," Natasha continued. "They did not care... [But] I really hope they can get through it, and figure it out. From all of this at least stay together, please. I mean, come on."
In the meantime, Natasha is going to continue looking for The One.
"If something happened in the future where I was single and I got a call, I would [do it] with bells and whistles... You guys got to see the rest of what happens on Paradise," Natasha concluded.
Earlier this week, Natasha thanked Bachelor Nation and fans of Bachelor in Paradise for supporting her and having her back when she was shown getting her heartbroken on the show.
"So much love and gratitude for every single person that has validated my feels on this wild paradise journey... I see you, I feel you, and the love has been unmatched," Natasha wrote on Instagram.
"Cheers to letting go of the past! Let the good times roll #bachelornation y'all know what's up."
Natasha had told Bachelor in Paradise cameras she felt "played" and "swindled" by "a con artist" who had "lied" to and "manipulated" her.
And when Natasha confronted Brendan about having lied about the extent of his history with Pieper, Brendan accused Natasha of having had "selective hearing" during their days together and said they had developed nothing more than "a friendship."
Natasha therefore later accused Brendan of "gaslighting" and being disrespectful to her on Twitter.
On the latest episode of Bachelor in Paradise, Brendan called Natasha, Demi Burnett and her friends "disgruntled females" after they accused him of wasting everyone's time in Paradise.
Brendan said his co-stars -- who told Brendan and Pieper they would leave the beach if they had any "dignity" left -- had made "a pathetic attempt to intimidate [him]" and that Natasha was just "salty."
Pieper whispered to Brendan afterwards, "I told you I didn't want to come. I told you."
Brendan and Pieper then decided to leave the beach on their own terms and continue their relationship at home.
"I didn't intentionally want to mislead anyone; I just withheld information," Brendan said in his final words.