During an appearance on Thursday's Today show, Cena revealed that he made Bella sign a "crazy agreement" before they moved in together -- and she did it "totally without question."
"I asked Nicole to move in with me simply because we were both living busy lives, and I wanted to show her that I was ready to be more serious. Now when I look at what I had done then and what I'm doing now, I wish I would've just asked her to marry me then," the WWE wrestler shared.
"I was very abrasive and stern, and she had to sign this crazy agreement to come to the front door," he continued. "[It was] just some sort of thing where I would be protected in case some sort of disaster."
According to Cena, Bella couldn't have been more gung-ho about signing the agreement, which only made him feel "super bad." "It also made me realize that, and this was very early on in our relationship, that this is one young woman I should not let get out of my life," he said. "Because when she says I'm with you because I love you, here's proof that I would still like to be here, here's proof... it was such a cold thing that turned into, for me, one of the biggest emotional hurdles."
As for whether Cena and Bella are planning to sign a prenup before tying the knot, he said yes, without hesitation, "to protect her."
"She is an independent woman and she has made her own money and she is proud of that and she has standards for that. If you speak to her, she would be like, 'I don't want anything from him. I want to do my own thing and make my own way, and she is absolutely doing that," he explained, adding: "Quite honestly, it's something we should never, ever, ever need. Ever."
The couple are in full swing planning their wedding, with Cena admitting that "this week was a big week."
"It's a weird thing that our relationship is public for the world to know, [but] what a good takeaway for the folks at home -- relationships are tough," Cena shared. "It's hard work, and a lot of times, it has to do with looking at yourself."