Prince William and Kate Middleton have never said this poignant word in their home in order to protect Prince George, Princess Charlotte and Prince Louis

According to a royal commentator, Prince William and Kate Middleton have never said the word 'spare' in their home to protect Prince George, Princess Charlotte and Prince Louis' healthy sibling relationship. 

• The word 'spare' is not on Prince George, Princess Charlotte and Prince Louis' 'radar' according to one royal commentator who believes the word has never 'been uttered inside their home.'
• Prince William and Kate Middleton do not use the word as they are 'determined to break the heir and the spare cycle' and keep their children part of their 'large loving family.'
• In other royal news, Kate Middleton took private parenting lessons ahead of Prince George’s birth.

As Prince George, Princess Charlotte and Prince Louis enjoy their summer holidays away from school, they may already be thinking about the upcoming new school year and wondering what best new school shoes and school supplies they'll be entering their new classes with. 

But while they're enjoying Kate Middleton's favourite creative summer activity and looking forward to the fun tradition that marks the end of The Royal Family’s summer stay at Balmoral, there is one thing that is definitely not 'on their radar.'

The Wales children, who currently sit second, third and fourth in the royal line of succession, have enjoyed a more informal upbringing than most royals as their dad, Prince William, made the promise that he would be a more 'hands on' father than his own one was. And one of the most important decisions he and Kate Middleton have made to this end is to avoid using a loaded and heartbreaking word in their home. 

In fact, they have done so well at shielding their kids from the word that one royal commentator believes the children don't even know what it means. 

So, what is this awful word? You might not be surprised to hear that it's the word 'spare.'

Royal commentator Kinsey Schofield told The Daily Star, "William and Catherine are determined to break the heir and the spare cycle.

"I don't believe the word 'spare' has ever been uttered inside their home to describe one or more of their babies. It is just not on their radar. They wanted to have a large loving family."

While 'spare' may have only just entered the public consciousness thanks to Prince Harry's tell-all memoir of the same title, the word has a long royal history and has been known to break apart many sibling relationships. 

The idea behind the royal saying 'an heir and a spare' refers mostly to royal and aristocratic families who need an heir to inherit a title or estate. The first born sibling is the heir, while the younger siblings are 'spares' who can step in on behalf of an heir should anything happen to them. 

Perhaps the most famous 'spare' in modern day is, of course, Prince Harry. In his scathing memoir, the Prince shared that, just after he was born, his dad King Charles III joked to his mother, the late Princess Diana, "Wonderful! Now you've given me an heir and a spare—my work is done."

Harry wrote that his 'spare' title followed him through all of his life and he was constantly reminded of his inferiority to his older sibling. He revealed, "They would say it without a spirit of judgement, but straight out. I was the shadow, the supporting actor, the plan B.

"I was brought into this world in case something happened to Willy."

It's likely that Harry's disdain for life as a 'spare' has influenced Prince William and Kate Middleton's approach to both the word itself and how they're parenting George's younger siblings. 

Kinsey Schofield explained that the couple are trying to instil royal duty in both Charlotte and Louis in the same way they're imparting it on George to ensure all three children understand their individually important positions. 

She shared, "William and Catherine are teaching their children about royal responsibilities through doing them. You will notice how poised and prepared the children seem to be during large royal engagements.

"You can tell that Princess Charlotte takes great pride in her family and responsibilities. [It reminds] me of the Princess Royal."