Prince William turns 37: Meghan Markle and Prince Harry under fire for 'cold' birthday message

Did Meghan Markle and Prince Harry snub Prince William with a "cold" birthday post? That's what some fans of the royal family are saying.

The Duke of Cambridge turned 37 on Friday, June 21, and the official Kensington Royal Instagram page shared a sweet photo of William smiling into the camera to thank followers for the birthday wishes.

"Thank you everyone for your lovely wishes on The Duke of Cambridge's birthday!" the caption read.

In the comments of the post, Meghan and Harry's official Instagram account, Sussex Royal, commented, "Happy Birthday to the Duke of Cambridge!" seemingly in lieu of an actual post to honour his birthday. Naturally, the couple got heat from commenters who thought that a simple comment wasn't enough of a celebration.

"He's your brother," one person wrote. "REALLY?"

"Wow, pretty cold," another follower commented. "And petty. Grow up."

"Really Harry and Meghan, you could of [sic] done a little better," another person proclaimed. "Are you trying to get everyone not to like you? We want the 4 of you back don't lose that bond you had with your brother."

Others called the comment "a shame" and wondered why there were "no birthday wishes for the future king at all" on their actual Instagram page.

While the Duke and Duchess of Sussex forewent a post for William's birthday, other member of the royal family did indeed share messages on their accounts: Clarence House, the account for Prince Charles and Camilla, Duchess of Cornwall, shared a sweet message for Charles' oldest son with a photo from 1984, the official Royal Family account shared photos of Wills with Queen Elizabeth and Prince Andrew, Duke of York, also shared a vintage snap from 1986.

Meghan and Harry's unceremonious birthday wishes for Prince William, especially in comparison to the rest of the royal family's, come just two days after the couple officially exited the Royal Foundation, the charity that they ran with William and his wife, Kate Middleton.

It was the second official split between the couples in the span of just a few months: This spring, Harry and Meghan moved out of Kensington Palace, where Kate and William live with their kids, and into Frogmore Cottage at Windsor Castle. They also formally separated their royal offices.

The official moves come after months of speculation that there's a rift between Harry and William, as well as Kate and Meghan. While the alleged tension seems to be mostly behind them, there may still be some lingering bad blood.

While royal experts say that "it's absolutely the case that the brothers did fall out" at some point amid tensions around Harry's new relationship with Meghan, sources now say that the duchesses and the brothers are bonding over parenthood and that Archie Harrison's arrival "has probably really helped to improve the relationship."