The couple's friends shared their surprise and joy as they offered congratulations.
Jamie Theakston wrote: "Wait... WHAT?", Ola Jordan added: "Congratulations" and Peter Andre shared some love heart emojis.
Rochelle Humes wrote: "Congratulations beautiful people" and Bunton's bandmate Victoria Beckham commented: "Congratulations. Love u both so much!! X."
Back in 2019, Bunton admitted she was in no rush to tie the knot with Jones. She said: "We haven't got to that stage. It is the world's longest engagement but if Goldie Hawn and Kurt Russell can do it . . . they've never married.
"Do you know what, I really do believe each to their own. For me, I am a one-man girl and as you can see I've been with Jade for so long and I love that kind of connection, that intimacy with one person, that falling in love.
"I love that. That's me all over. But I honestly think everybody is wired differently and why shouldn't anyone feel and do and love whoever they want?"
However, she admitted she wanted to marry "one day".
Asked if the lack of making things official has kept them together, Bunton said: "Maybe it is, I don't know. One day I know we would love a wedding and we want the kids to be there. I really feel for other people who struggle.
"I read all the stories like everyone else. It's not nice, this industry is fast, you travel a lot, you're in and out of studios for long hours and overnight so I know how difficult it is.
"But we met young, we grew up together. We have a lot of respect for each other and he really supports me and everything I do. Jade is more patient than me, 100 per cent. He is the patient one."
