Prince George is too cute!

In a new interview, a close royal family friend dished George — who turned age three on July 22 — is already acting like quite the gentleman!

"He's a little boy now," the insider revealed to People. "A proper little chap!"

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The family friend additionally revealed Princess Charlotte's older brother is even attending preschool three days per week at Westacre Montessori near Prince William and Kate Middleton's country home in Norfolk, England. George is growing up so fast!

Click through the gallery below to see George and Charlotte’s cutest photos!