The royal family is not the most stellar people in relationships. With the history of affairs and divorces in the past, it is no question why Britons feel at ease with Prince William and Kate Middleton’s relationship.

The royal pair who have been together for almost a decade now has only shown resiliency and strength. Sharing three children, they have become the picture-perfect royal family.

A report from Express UK reveals why the couple’s marriage works so effortlessly. According to Express, Prince William and Kate Middleton had a "secret" marriage pact before William got down to one knee.  

Royal expert Kate Nicholl wrote in her book "The Future Queen," the pair agreed to a pack during their Seychelles vacation.

They have just had a massive fallout before this vacation, and to cement their relationship, they came to an understanding. Apparently, the Duchess herself told Prince William to "let off some steam" as part of their contract.

In the weeks after their vacation, the Prince was seen dancing with an unknown blonde girl in a club following his and Kate’s reconciliation.

The couple also ended up agreeing to terms that involved Prince William graduating from his ARMY training and his Navy and Royal Air Force duty.

Because of this "secret" marriage pact, Kate was dubbed by the media sa ‘Waity Katy,’ in response to what seemingly was a very long and agonizing wait for Prince William’s proposal.

The pact also raised Kate’s awareness regarding her future as Queen, and royal expert Tom Quinn expressed how the Duchess had to evolve her styling and dressing style to be more modest.

"Her clothing almost began to reflect what people saw in her character, a kind of restraint, kind of modesty almost,” Quinn said.

Despite Kate having to wait over 10 years for Prince William to propose to her, much of Britain has already accepted the faith that was bestowed to Kate Middleton due to the longevity of their dating history.

She was to be the Queen in the near future. This also made it easier for Kate to transition from being a commoner to a royal member and was well accepted within the family household.

Recently, the pair celebrated 10 years since their engagement in the past few days, and people are swooning at the fact that they have stayed strong together in all the adversities they have faced.