In the blink of an eye, she is seen standing next to the former Manchester United footballer while flaunting her big baby bump in a long black dress.
Kate wore her blonde locks in loose waves and finished her look with gold earrings.
Rio wore a dark blue three-piece suit as he and Kate smiled in their kitchen.
In an instant, the former footballer posed with Tate and Lorenz, who wore tuxedos, and had their faces covered in smiley face emojis.
Another heartwarming snap showed Rio talking to her daughter who wore a black dress and a bow in her hair.
Kate also shared a photo of a menu, prepared by the kids, consisting of a garlic prawn appetizer, tenderloin steak, and homemade fries.
On the dessert menu there were apple crumble, chocolate brownies or strawberries and meringue.
Kate captioned her post: “Happy birthday to YOU ok so we decided to get dressed and surprise dad when he came home from work… the dinner cooked by the children’s birthdays isn’t that bad after all.” ”
Kate hit back at online trolls earlier this week who told her Rio and his late wife Rebecca’s children were her “family”.
She was attacked on social media after declaring that her first three children were “family” since she is raising them as if they were her own.
A troll wrote: “Ooof. Rebeccas family. I’m all for mother-in-law, etc. And you walked into a huge hole. But these children are Rebeccas. And they won’t thank you for saying the opposite xx. ”
She called the trolls “stubborn” and “sad” when responding to comments made on her Instagram post.
She responded by writing, “Wow. Very, very narrow-minded. Rebecca is there mom and will be forever – a mom can never be replaced. But let me clarify WE ARE a family, families are not just about blood, but who is there for us and loves us unconditionally.