And aside from being a caring fatherly act, there's a reason why the father of two insists on holding his son's hand - parenting expert Jasmine Peters believes it's to prepare Prince George as king.
'It is not uncommon to see a father with his son to set the foundation of what his role and responsibilities will be in life with a family,' she told the Daily Mail.
'It is often believed that it takes a man to raise a boy to be a man. Yes, it could reflect that Kate and William are traditional, but it also reflects the importance of the bond created between father and son and mother and daughter that they both treasure and hold dearly as responsible and loving parents.'
Prince William and Duchess Catherine have been praised for their down-to-earth parenting approach to their children.
A source told US Weekly, the Royal couple are dedicated to helping their children receive a normal upbringing.
'George loves anything on wheels and gets to spend hours writing bikes,' they said. 'Charlotte, meanwhile, plays Disney princesses while happily unaware that she heads the title herself.'
No doubt the royal youngsters are looking forward to their new sibling!
This article originally appeared on New Idea.