Stepping out alongside the birthday girl in matching outfits, Mike quipped: "I can’t believe she's letting me play golf on her birthday. What a legend!" in a post on Instagram, alongside a red love heart emoji.
The photo accompanying the dad-of-four's words showed Zara beaming in white jeans and a mint green golf polo top, her look complete with a navy blue cap. Meanwhile, Mike rocked the same mint green top as his beloved but chose a rather playful pair of golfing trousers, something he is known for sporting when it comes to his yearly fundraiser.
The pair in question were in keeping with his mint-green colour palette and were verdant shades of the colour wheel from dark forest green to a soft grey hue.
"Are those Minecraft trousers?? Totally love them MT," one fan replied in the comments. A second added: "And wear those trousers…." Meanwhile, Denise Van Outen added a heart eyes and red love heart emoji.
One moment from the day saw Zara abandon her beau for want of hanging out the side of a golf buggy, not only draped with a glittery pink throw and adorned with matching grey and green balloons, but emblazoned with eyelashes and large red lips.
No doubt Zara will mind Mike's day of golf as not only is the equestrian a keen golfer herself but she was also joined at the event with her former sister-in-law, Autumn Phillips and close friend and her mother's Lady in Waiting, Dolly Maude.
Zara and Autumn's reunion comes just weeks ahead of Peter Phillips' wedding to Harriet Sperling. Autumn and Peter share daughters Savannah, 15, and Isla, 14, who are incredibly close with Zara's daughter Mia, 12.
Canadian-born Autumn and her former husband, Peter, finalised their divorce in 2021, after announcing their separation two years prior.
Autumn and Peter tied the knot at St George's Chapel in Windsor in May 2008, with the bride wearing a gown designed by Sassi Holford. Her mother-in-law, Princess Anne, also loaned her the Festoon Tiara, while Zara was one of her bridesmaids.