Nikki Bella Gives A Big Reason Why She Broke Up With John Cena

John Cena and Nikki Bella

Nikki Bella insists her most recent break-up with John Cena is the real thing — and not a staged storyline for reality-show cameras.

“It’s just hard for me to relive those moments,” she told PageSix.com of her E! reality series Total Bellas, which follows her and sister Brie’s adventures as they transition from the wrestling ring to the business world.

In the season finale that aired on July 29, Nikki broke off her engagement with Cena. It was the couple’s second break-up in a matter of months — and it was big news online and in the tabloids.

“People said it was fake for ratings, [but] don’t you think a wedding would be best for ratings? I would never fake a break-up,” Nikki explained. “And when people keep questioning it, it actually makes your heart ache even more.”

After over four years of dating, Cena proposed to Nikki in the ring last year at Wrestlemania 33. But just weeks before they were set to tie the knot in May, Cena broke things off, saying he didn’t want children (the scene played out on Total Bellas). However, they rekindled their relationship after he agreed to be a dad — only for Nikki to then call it off.

Despite kids seemingly being the deal-breaker in their relationship, Nikki has — at least temporarily — changed her mind.

“She has been the best form of birth control for me,” Nikki said of her year-old niece, Birdie, who is Brie’s daughter. “Here I was dying to be a mom. Now I want to push it back. Can my clock tick until my 40s?”

Now, one of the big issues keeping her and Cena apart is ambition.

“One person had to sacrifice their career [for us to be together], but I’m not willing to do that,” Nikki said, who is instead pouring herself into work while Cena films a movie in China until ­October.

“I’m just not the girl who hangs out on set. I have my own career,” she added. “I want to be one of Forbes’ top entrepreneurs.”