An insider tells PEOPLE that Prince Harry "wasn't the only dad there" when he joined Archie and wife Meghan Markle at a local playgroup

Archie already “loves” playgroup — and now dad Prince Harry is making playtime even better!

The 35-year-old royal dad accompanied his six-month-old son and wife Meghan Markle to a playgroup session near their Frogmore Cottage home in Windsor for the first time this week, a source confirms to PEOPLE.

“There were a couple of other dads there — he wasn’t the only dad there!” the insider tells PEOPLE of the outing, which was first reported by Daily Express.

“Archie had a fantastic time. He was crawling around and was particularly taken with two other red-haired babies,” a source told the outlet. “The Duke said: ‘Gingers stick together!’ ”

“It was a lot of fun,” the Duchess of Sussex said. “He loved it.”

Archie Harrison Mountbatten-Windsor
Prince Harry, Meghan Markle and Archie
| Credit: PA Wire/PA Images
Prince Charles, Prince of Wales, Prince Harry, Duke of Sussex, Archie Harrison Mountbatten-Windsor
Prince Charles, Prince Harry and Archie
| Credit: Chris Allerton © SussexRoyal

Little Archie just shared his birthday wish for Prince Charles as his proud parents released a new portrait taken at the baby royal’s christening.

Posted on their @SussexRoyal Instagram page, the previously unseen photo shows grandfather Charles, who turns 71 on Thursday, admiring at his latest grandson after the ceremony at Windsor Castle in July.

“Happy birthday to His Royal Highness The Prince of Wales – Sir, Pa, Grandpa!” the couple wrote, adding a cake emoji. The picture was taken by the Duke and Duchess of Sussex’s wedding photographer Chris Allerton.

Prince Harry, Duke of Sussex, Meghan, Duchess of Sussex and their baby son Archie Mountbatten-Windsor
Archie, Meghan Markle and Prince Harry
| Credit: Samir Hussein/WireImage

Archie is already working on his royal smile. Meghan shared a new milestone for her son during a surprise outing with military families earlier this month. As she met a group of young children at the Broom Farm Community Centre in Windsor, Meghan told one little girl, “Look at all your little teeth! Archie’s just got two teeth.”

She pointed to her bottom lip as she added, ”Two tiny ones right there.”

Meghan Duchess of Sussex and Archie Mountbatten-Windsor
Archie and Meghan Markle
| Credit: Tim Rooke/Shutterstock

It’s unclear when royal fans will see the Sussex family next. It was previously revealed that Meghan and Harry will take about six weeks off towards the end of the year to spend some valuable “family time” together amid their concerns that the intense scrutiny they’ve faced has been tough on the couple.

“The duke and duchess have a full schedule of engagements and commitments until mid-November, after which they will be taking some much-needed family time,” a royal source confirmed to PEOPLE.

And it was shared earlier this week that Meghan and Harry are skipping the annual holiday festivities at Sandringham — including their public walk to church on Christmas morning — with Queen Elizabeth and the rest of the royal family.

Christmas Day church service, Sandringham, Norfolk, UK - 25 Dec 2018
Prince Charles, Prince William, Kate Middleton, Meghan Markle and Prince Harry
| Credit: Tim Rooke/REX/Shutterstock

“The Duke and Duchess of Sussex are looking forward to extended family time towards the end of this month,” Buckingham Palace said in a statement on Wednesday. “Having spent the last two Christmases at Sandringham, Their Royal Highnesses will spend the holiday this year, as a new family, with the Duchess’ mother Doria Ragland. This decision is in line with precedent set previously by other members of the Royal Family, and has the support of Her Majesty The Queen.”

The palace didn’t specify where they will be ringing in the holiday, but a source tells PEOPLE that they will not be spending it in Meghan’s hometown of Los Angeles, where Doria lives.