There's a lot about the royal family that's shrouded in mystery, but thanks to a new BBC documentary, Prince, Son and Heir: Charles at 70, the curtains of Clarence House are being lifted. The Daily Express reports that a sweet moment was captured in the doc that few people saw: a tender meeting between Prince Charles and little Prince Louis.

The footage comes courtesy of John Bridcut, who had unprecedented access to Charles and the royal family for a year while he worked to give fans a look at royal life. It was also a chance for Charles to show the world a softer side of himself, which was clear in this touching moment. The Express notes that this specific moment took place in September, when Kate and William paid a visit to Charles and Camilla.

Prince Charles Funeral Of The Countess Mountbatten Of Burma
Credit: Max Mumby/Indigo/Getty Images

Prince, Son and Heir: Charles at 70 (which is being released to coincide with Charles's 70th birthday) also gave his wife, Camilla, a chance to tell viewers about Charles when he's out of the spotlight.

"He will get down on his knees and crawl about with them for hours, you know, making funny noises and laughing and my grandchildren adore him, absolutely adore him," she said of how Charles interacts with the royal kids. "He reads Harry Potter and he can do all the different voices and I think children really appreciate that."

William had a chance to speak about his father, too. In an interview, he said that when Charles makes time for his grandkids, everyone is all smiles and having a great time. It just doesn't happen enough, William adds. Hopefully, Charles will get a chance to watch the documentary and see just how much his family loves spending time with him. That way, he can give William and Harry a little bit of the royal workload and spend some time with the new arrivals.

"So, having more time with him at home would be lovely, and being able to you know play around, err, with the grandchildren," William explained. "Cause when he’s there, he’s brilliant. But we need him there as much as possible."