John Cena Reportedly 'Bitter' Over Nikki Bella's Plans for Tell-All Book

Following a very public breakup, WWE star and Total Bellas star, Nikki Bella is reportedly working on a memoir about her life, with In Touch Weekly adding how her ex John Cena is "scared" of what she will reveal.

According to the publication, Bella is keeping Cena on his toes with the upcoming memoir with an insider revealing details of how the pro wrestler turned actor is growing a bit "bitter."

"John heard that Nikki is writing a book, and he's clearly doing some damage control. That's why he's tweeting," the source revealed to In Touch Weekly. "There's clearly still some bitterness between them. Nikki and her sister, Brie Bella, had a book deal. I don't know where that stands now, but Nikki now has a lot more to say. She's now working on a new book."

The source goes on to add that Bella's memoir will detail how women can feel empowered and inspired.

"Nikki has always wanted to empower women and her fans, so it will be part memoir and part inspirational," the source continued. "How could she not write about such a crucial life event — meaning John and her broken engagement — which wasn't easy. But in the end, it did make her stronger. John heard about the book, and he's trying to get ahead of it."

Last week, Cena wrote a cryptic message on Twitter about his relationship with Bella, sharing how users should "beware those who think you owe them happiness at the expense of your own well-being."

While Bella did not publicly respond, she did tweet her own message that seemingly shaded her ex that raked in a supportive response from fans.

"When you don't give him what he wants, he will delete you, silence you, manipulate you, do what he can to destroy you, but turn that hurt into strength," Bella wrote. "Take the high road and prevail! Happiness can't be bought, it is priceless. It's your true secret weapon. N."

After six years together, Cena and Bella called it quits last July. Since then though, the former couple has moved on with Bella dating her former Dancing With the Stars partner, Artem Chigvintsev, while Cena has been reportedly linked to Shay Shariatzadeh after the two were spotted on a date in Vancouver this past March.