"Happy anniversary! 8 years later… And I love you even more @christianhorner [heart emoji]," the Spice Girls star wrote in her caption, while the Formula One boss added: "Happy 8th Wedding Anniversary to my beautiful and incredible wife @therealgerihalliwell. xxx."
One of the stunning shots showed Christian and Geri from their wedding day, which took place on 15 May 2015, with the groom looking absolutely besotted as he first laid eyes on his bride.
Fans of the pair rushed to post comments, with one writing: "Much happiness to you! The main thing is that you are happy Geri." Another said: "You're an elegant couple." A third post read: "Lovely to see you happy, Geri. We love you."
Geri, 50, and Christian, 49, began dating in February 2014 before announcing their engagement nine months later. Since their marriage, they have amassed a £440million fortune and have welcomed a son called Monty, who is now five. The former singer is also a mum to her 17-year-old daughter Bluebell, while Christian has nine-year-old Olivia with his ex-wife Beverley Allen.
The couple are notoriously private about their personal lives, but in a recent interview, Christian gave fans a candid glimpse inside their love story – which didn't have the smoothest start! During a chat with The Telegraph in March, the Red Bull team principal revealed how they actually crossed paths a couple of times before they started dating in January 2015.
"She was a guest of Bernie Ecclestone's in Monaco one year and came down the pit lane," he revealed of the first time they met back in 2009. "I remember [McLaren boss] Ron Dennis was standing next to me and Eddie Jordan was there as well.
"Anyway, she gave Ron a kiss on the cheek, and she gave Eddie a kiss on the cheek. So I thought, 'OK, I'm on for a kiss on the cheek here!' And I went to give her one and she shoved her hand out at me!"
A few years later, they embarked on a relationship – at the time, it was reported that Christian's parents were unhappy with him after he split from his partner of 14 years, Beverley, shortly after she gave birth to their daughter Olivia.
Confirming that his parents are supportive of their marriage, he said: "I have a great relationship with Beverley and Beverley gets on with Geri, and Geri is great with Olivia and Olivia has a lovely relationship with Monty. It's totally harmonious."
Of the critics – who thought their relationship was doomed – Christian added: "You know, life works in mysterious ways. I didn't marry Geri because she's a Spice Girl. I married her because I fell in love with her.
"It will be ten years this time next year and we've been happily married for seven. We're very different characters but we complement each other well."
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