The Duke of Cambridge celebrated his 37th birthday last week, and we're sure Kate, George, Charlotte and Louis made sure he had a really special day.
But many people have raised eyebrows at how Prince Harry and Meghan Markle publicly marked the occasion.
Instead of sharing a photo of him on their Instagram page, as they have done with the Queen and Prince Philip, they simply commented on the photos Kensington Palace posted.
Ingrid Seward, the editor in chief at Majesty Magazine, said the thought it was "pretty rude" that the Sussexes didn't do more to mark the day.
She told Sun Online: "I think it’s a snub if they don’t leave one for Prince William as they did for the Duke and for the Queen.
"If they don’t I think it’s pretty rude and will certainly be construed as purposeful.
"That is the trouble with Instagram, it becomes your slave.
"But it's not as if it’s a cousin or a friend – it's Harry’s big brother."
However many fans don't believe there's anything wrong with Harry and Meghan's comment, pointing out that they did the same thing for Princess Charlotte and Prince Louis's birthdays.
However the message for William was much more formal than the ones they sent to their niece and nephew.
Previous comments had featured warm messages such as "lots of love" and contained kisses and emojis, but this one noticeably did not.
The birthday message came the day after Meghan and Harry revealed they were splitting from the Royal Foundation, the Fab Four's charity.
Kate and William will continue the original charity while the Sussexes set up their own, new foundation.
The charity split statement says both couples are "incredibly proud of what they have achieved together" but claims the new structure will "best support Their Royal Highnesses with future charitable activity".
However many fans were worried this is another sign of a growing rift between the two royal couples.
The charity split is the latest way the two couples are cutting their ties to each other.
Last year Meghan and Harry split from the Kensington Palace household, setting up their own office within Buckingham Palace.
Before Archie was born, the couple moved out of their palace home, which was just a few doors up from Kate, William, George, Charlotte and Louis, and set up their new life in Windsor at Frogmore Cottage.