The 41-year-old WWE star had a change of heart about children in a preview for Sunday's episode of Bella's E! series Total Bellas.
"I can't have you out of my life, ever. I want to marry you. Relationship and marriage, especially, is about sacrifice, and I will make that sacrifice for you," he told Bella. "I will give you a child."
Bella ended her engagement to Cena in April after five years of dating, in part due to his refusal to have kids. She stressed how important having a family is to her in the episode.
"I see the point of having kids after you've been with someone for so long," the 34-year-old television personality said.
"I feel like there's so much more I want to do with you and experience with you. It's just wanting to be a mom and knowing you will not be a dad," she told Cena. "I've just come to the realization that I'm not okay with it."
Bella and Cena have yet to confirm their relationship status, although TMZ reported the pair were spotted at dinner Tuesday in San Diego. Bella's rep told E! News this month the pair are taking their relationship "day by day."
"Nikki Bella and John Cena are working on their relationship," the rep said. "They appreciate all of their fans and their continued support."