Fiction is full of little princes and princesses. But for Prince George, 11, Princess Charlotte, 9, and Prince Louis, 6, life is more realism than fairy tale.

“The world doesn’t get to see that they’re just normal kids, acting up and being silly like most children,” says an insider of Prince William and Princess Kate Middleton’s three offspring, who are being brought up away from London’s Buckingham Palace in Windsor, England. “Kate and William are raising happy, well-adjusted kids.”

Each of the children has their own personality — and knows how to get under one another’s skin. “They all have their cheeky sides that come out in private,” explains the insider. “For the most part, George and Charlotte are very close and well-behaved, while Louis is the instigator.”

Regardless, the older siblings are patient with their occasionally annoying little brother — which is something their royal parents, both 42, more than appreciate. “George and Charlotte understand that their role is to teach Louis right from wrong,” shares the insider. “But George still thinks Louis gets away with more bad behavior than he ever did!”