'The Bachelor' Preview: Zach Breaks His 'No Sex' Rule During Fantasy Suites

'I let the women down by saying one thing and doing another,' Zach admitted.

Zach Shallcross' final weeks as the Bachelor won't be smooth sailing. At the conclusion of Tuesday night's "Women Tell All" episode of The Bachelorfans were treated to a look at the drama ahead during next week's Fantasy Suites.

Things start out on a positive note, with Zach telling the cameras he's "so in love," as Kaity, Gabi and Ariel all profess their deep feelings for the tech executive. It's when Zach implements a no sex rule that things go downhill.

"This week is viewed as sex week. This is the week where s**t can hit the fan," he says. "It's not conventional, but I decided that there will be no sex of any kind for Fantasy Suites."

Despite his intention not to get intimate with any of his women, Zach ends up doing just that with one of his finalists. 

"Something really special happened. Waking up this morning, I've had this pit in my stomach," he says. "I feel like I let myself down and I feel like I let the women down by saying one thing and doing another."

When Gabi learns some upsetting news, she tearfully says, "It's not fair. What the f**k am I supposed to feel? Why am I putting myself through this pain? I don't know why I'm doing it to myself."

Meanwhile, Kaity questions, "How am I to keep moving forward? I'm confused. I feel distant from him. I'm not happy. I literally just want to go home."

Zach can only hope that all the drama will eventually lead him to his person.

"Coming into this, I wanted to do the right thing. I went with my head and not my heart and that was the worst thing I could've done," he says. "I've caused pain and I've made mistakes, but true love is worth fighting for."

When ET spoke to Zach about the journey ahead, he admitted that the "emotional season" was "very overwhelming at times." Meanwhile, host Jesse Palmer told ET that Zach has been "so authentic" through it all.

"Everything's about to turn onto its head. We're going to be involved in a situation that I don't think we've ever had on the show before," Jesse told ET. "This is not what Zach had planned and he is going to have to dig deep to try to pull himself out of this. This is going to be more dramatic and more emotional by leaps and bounds versus anything that we've seen this year."

"I'm excited that people have gotten to watch him this season, because they're learning a lot about him and they're seeing who he truly is. I can tell you, Zach is... the same guy he is that you see on television," Jesse said. "Zach is mature beyond his years. He is an emotional guy. He wears it on his sleeve. Zach can make decisions. He can make tough decisions. He can make them by himself. He can make them quickly. Cares about the women, cares about his time with them. He's very intentional."

"You can say whatever you want to say about Zach, but I think people are figuring out now why he is the Bachelor. He's been amazing, in my opinion," Jesse added. "He was perfect to do this. He has all the qualities you need and I think people are going to continue to see that as the season unfolds."

The Bachelor airs Mondays on ABC. Stay up to date on all the drama with ET's coverage of Zach Shallcross' journey for love.