Prince William, Prince George, Princess Charlotte and Kate Middleton
Prince William, Prince George, Kate Middleton and Princess Charlotte arrive at the Victoria Airport on Sept. 24, 2016 in Victoria, Canada. Getty Images/Chris Jackson

Kate Middleton and Prince William’s three children may be placed in an unusual position due to the Succession to the Crown Act 2013. When Prince George, Princess Charlotte, and Prince Louis are much older, they may face different protocol requirements.

The Succession to the Crown Act 2013 states that only the first to sixth in line to the throne need to ask Queen Elizabeth II’s permission to tie the knot. In the current line of succession, Prince Harry is the last person who needed to ask for Her Majesty’s permission before she got engaged to Meghan Markle.

MP Christopher Pincher asked years ago while the act was still being debated where the number six came from. Pincher is curious why the act doesn’t end after the third, fifth, and even the 12th in line to the throne.

“If we put in place a rule which says that the monarch can and must give consent to the marrying of the six persons nearest in line to the throne, imagine a scenario where a monarch has three children, who each have two or three children. The monarch will soon be in the invidious position where grandchild number four, who is fifth-in-line to the throne, must seek the consent of the monarch to marry, but grandchild number six, who is seventh-in-line to the throne, need not seek that consent,” he said.

At the end of the day, Pincher said that the act doesn’t seem very fair to some members of the royal family. And since it has already been put in place, it is likely for Prince George, Princess Charlotte, and Prince Louis to be affected by it.

There are also rumors suggesting that Prince William and Middleton would eventually have a fourth child. This means that the fourth child would fall on either side of the number six requirement.

When this happens, Prince Harry will be seventh in line to the throne.