Prince Harry and Meghan Markle haven’t even walked down the aisle yet, but that isn’t stopping the prince from thinking about his future royal babies.

Katie Nicholl, royal expert and author of "Harry: Life, Loss, and Love," recently shared with Entertainment Tonight that Prince Harry is very "keen" to have children as soon as possible.

"My sources are saying that Prince Harry, particularly, is very keen to start a family, pretty soon after the royal wedding," she said. "He's made no secret about wanting children."

Nicholl added that Harry's love for his little niece and nephew, Princess Charlotte and Prince George, really sealed the deal for him.

"I think that moment [for Harry] really kicked in when his brother, Prince William, of course, settled down with Kate Middleton," Nicholl said. "That has definitely gotten Prince Harry pretty broody."

Harry may not be the only one with baby fever, however. Meghan has already met both George and Charlotte, and according to Nicholl, she's completely smitten.

"The reason he wanted Meghan to meet Prince George and Princess Charlotte was so she could see that — this would be hopefully replicated by them, that they would go on to have children," Nicholl said. "That you marry into the royal family, but that doesn't mean you can't have a regular family with cute children, and here are George and Charlotte to show that that can happen. That was really important to him."

Though, it’s key to note this is speculation from one person. Who knows, Meghan and Harry may instead choose to live out their lives as the “cool” aunt and uncle to the royal children.

If they do decide to add a few more little ones to the Windsor family, their children will be fairly far down the line of succession. As it stands, Harry is sitting as sixth in line to the throne, behind his grandmother, father, brother, and his soon-to-be three children. Though, you never really know, Queen Elizabeth was also a “spare heir” until her uncle, King Edward VIII, abdicated the throne in 1936. So if for some reason William decides ruling the monarchy isn’t for him, and his three children decide the same, there would be hope for a King Harry.