According to a royal source the Duke of Cambridge, who was born two years to the day his future in-laws tied the knot, invited them to spend their 34th wedding anniversary at his and Kate's Norfolk home for a double celebration, which also marked his 32nd birthday.
"William invited them to Sandringham," said a royal insider. "He wanted to show them around Anmer Hall.
The Duke and Duchess of Cambridge
"They had a barbecue on Saturday afternoon," they added. "Mike helped William, while the ladies entertained Prince George."
The day after his birthday Prince William left the celebrations to play in a charity polo match while it is believed Kate stayed on at the country home with her parents and Prince George.
Carole and Michael Middleton
Carole and Michael's weekend with William, Kate and George is testament to their close relationship.
When Kate was suffering acute morning sickness in the early stages of her pregnancy, she and William chose not to spend Christmas with the British royals at Sandringham and instead went to Carole and Michael's home in Bucklebury.
The couple also headed to the Middleton's Berkshire home in the days after Kate gave birth to Prince George.
In January 2013 the Queen allocated Anmer Hall to the Duke and Duchess of Cambridge as a country retreat.
The listed ten-bedroom Georgian property, which is two miles from the Queen's residence on the Sandringham Estate, has since been undergoing renovations including re-routing of the driveway, extensive tree planting to shield the property, and plans to expand accommodation.