John Cena is willing to have surgery to have children with Nikki Bella

However, the 'Blockers' actor has since had a change of heart and is now open to having a family, but it seems there have also been medical reasons behind his unwillingness to have kids.

In scenes aired on Nikki's reality show 'Total Bellas', the former couple reunited for a romantic dinner and John said: "I wanna marry you and relationship and marriage especially is about sacrifice, and I will make that sacrifice for you. I will give you a child."

Nikki replied: "But you have the..."

John said: "I know. I physically can't have kids. So, I'm also telling you that I'm willing to have surgery and then still go through with being a dad."

Nikki was initially stunned by the 41-year-old sportsman's promise.

She said: "You're sure though? Are you gonna change your mind?"

When John promised he wouldn't go back on his word, she exclaimed: "Oh John, you're gonna be the most amazing dad in the world."

The 34-year-old star was so thrilled by John's pledge, she jumped across the table into his arms.

She later admitted to the camera: "I think I'm gonna leave here as a fiancée. I think, yeah. I am still the soon-to-be Mrs. Cena."

John recently made a public plea to win Nikki back on TV show 'Today', in which he promised to rethink the family issue between them and it seemed to have done the trick.

Nikki watched the interview with her sister Brie Bella and she admitted on their show: "It's kinda confusing right now watching John's interview on the 'Today' show because last we talked, that pretty much was it. If I wanna be a mom, there's no John."

Brie reassured her: "I just think that in that interview John could've went two different ways. He could've said, you know, 'This was a beautiful relationship. I learned a lot, but we're going our separate ways.' Or he could say what he did say."