The former Spice Girls star, 42, chose to announce her happy news in a rather discreet and understated way, placing a small advert in The Times paper that was picked up by eagle-eyed readers.
Her notice read: "The engagement is announced between Christian, son of Mr and Mrs G M Horner and Geraldine, daughter of the late Mr L F Halliwell and Mrs A Parkinson."
It's a move we saw last week as well, when Sherlock star Benedict Cumberbatch revealed his engagement to theatre director Sophie Hunter in a simple Times notice.
Is this the way forward for celebs? Goodbye, Twitter, hello newspaper announcements?!
Geri and Christian, 40, are thought to have begun dating in March this year, with a source telling The Mirror at the time: "Geri and Christian get on really well and they have lots to talk about. He's been really good for her and they are very relaxed about people seeing them together.
"She's been gushing about him to a lot of friends and it seems like this one could be for keeps. They are both parents and have lots in common in that respect."
Geri is a mum to daughter Bluebell, while Christian also has a daughter from a previous relationship.
So far, Geri has yet to reference the engagement on her Twitter account. Her most recent post was congratulating Cheryl Fernandez-Versini on breaking a chart record she had previously held herself.
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Celebrity engagements of 2014:
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