"John and I might be calling off the wedding again," Nikki Bella tells twin sister Brie in this exclusive sneak peek from Sunday's Total Bellas

After calling off her May 5 wedding, Nikki Bella‘s reasons to break up with John Cena became more clear.

PEOPLE has an exclusive sneak peek at the Total Bellas midseason supertease, during which the WWE star, 34, tearfully tells her twin sister Brie Bella and mother Kathy why she struggles with her decision to end their relationship after six years together.

“I’ve been miserable and I’ve been trying to be happy, but I realized there’s just such deeper problems,” Nikki says with tears in her eyes.

Later, Brie does her best to console her sibling, telling Nikki, “He’s wanted a strong career, and he has that. Unfortunately, to have that he lost the woman of his dreams.”

Despite the split, Nikki keep her bachelorette party plans in Paris as she hosts Brie and their friends for the nine-day soirée. And it appears that Nikki and John may have briefly reconciled, as she tells Brie, “John and I might be calling off the wedding again.”

Nikki Bella
| Credit: E!

In May, Nikki called off the engagement three weeks before she and John would walk down the aisle during their destination ceremony. Sources previously told PEOPLE that her decision to break up was due to their differing stances on marriage and having kids.

Teen Choice Awards 2016 - Red Carpet
John Cena and Nikki Bella
| Credit: Kevin Mazur/Fox/Getty

PEOPLE confirmed earlier this month that they are officially back together.

The pro wrestlers had been open about their desire to reconcile, with Nikki previously telling PEOPLE that she’d been in “communication” with her ex.

Around the same time, Cena publicly confirmed that after years of insisting he had no desire to start a family, he’d had a change of heart.

“I would love to be a dad,” he told TMZ. “I dedicated my life to my work, and now I’m realizing that there is life, and life exists, and it’s beautiful, and I think part of that is being a parent.”

Total Bellas airs Sundays (9 p.m. ET) on E!