Speaking to Vanity Fair, the parent revealed: "He's very popular and has lots of friends, and there's little fuss made about who he is."
So popular in fact that the five-year-old's friends call the young royal by the nickname Tips, which is also apparently what the Duke and Duchess call him at home.
The parent went on to reveal that William and Kate always make the effort to drop their son off at school.
"...They are always friendly."
But it's William who is always keen for a chat.
"William particularly loves to have a chat with some of the other parents and he works out with some of the mums at Harbour Club after drop off. He's very chatty and amiable."
Last year, another parent told the Daily Mail that the royals are treated no differently by parents and staff and the prestigious school.
"No one really gives Kate a second glance when she does the school drop off," they told the publication.
"We have a Victoria's Secret model doing the school run, too, and the dads are far more interested in her."