Harry's proud dad moment while giving Archie update

Prince Harry has stayed pretty tight-lipped when it comes to his young son Archie Mountbatten-Windsor, but he had a very proud dad moment while sharing an update last week.

The Duke of Sussex revealed to a group of school children that his little boy is doing well, though isn't so little anymore.

While visiting a high school in Luton, near London, on Thursday a young girl asked him "how everything was going" with Archie.

"He's doing really well, thanks, he's getting so big," Harry responded, clearly proud of his growing bub.

LISTEN: Tune in to 9Honey's royal podcast, The Windsors, to hear all about baby Archie's arrival.

The royal dad went on to chat and play with the school students, encouraging them to get active and play sport, something he'll surely be doing with Archie once he's a little older.

Though pictures of Archie have been few and far between, Harry and wife Meghan Markle working to ensure their son's privacy in his younger years, the few sightings of the newest royal have shown him to be steadily growing.

Fans were treated to a new shot of the bub on the Sussex Royal Instagram over the weekend.

The royal parents shared a sweet never-before-seen shot of themselves with their son on his christening day, showing Meghan cradling Archie on her lap while Harry crouches down to look at him, resting his hands on his wife's legs.

The photo was shared as part of a photo collage of Harry for his birthday, the prince celebrating as he turned 35 over the weekend.

"Your service to the causes you care so deeply for inspires me every day," Meghan wrote to her husband on the touching post.

"You are the best husband and most amazing dad to our son. We love you. Happiest birthday!"