Kate Middleton’s Sweet Nickname for Prince Louis Heard Again in Latest Video Message

Immediately after saying these words, Kate’s voiceover begins, where she shares that “As the summer comes to an end, I cannot tell you what a relief it is to have finally completed my chemotherapy treatment,” she said. “The last nine months have been incredibly tough for us as a family. Life as you know it can change in an instant, and we have had to find a way to navigate the stormy waters and road unknown.”

At the start of the video, Louis walks ahead of his parents and two siblings, throwing a ball as they venture through the woods. Later on in the video, Louis can be seen being pushed by his mom on a swing, and viewers can even hear his voice in the clip as he leans into the camera and says, “Hello, hello.”

The Sept. 9 video wasn’t the first time Kate used the “Lou Bug” nickname while in public. On May 8, 2023, while taking part in his first royal engagement, Louis joined his family for The Big Help Out event in Slough. The family of five joined the 3rd Upton Scout Troop for the occasion just two days after King Charles’ coronation, and at one point took part in toasting marshmallows together to make s’mores.

“Pop that in the fire, Lou Bug,” Kate could be heard saying as she told her youngest to discard a stick in the fire.

That same day, Louis shoveled sand into a wheelbarrow and pushed the wheelbarrow over to other volunteers as his mom stood close by, encouraging him.

“Well done, good job Lou Bug,” Kate said to Louis, who had just turned 5 at the time.

“Louis was very enthusiastic and did a good job,” said Anne Edwards, an adult Scout helper who worked with Princess Charlotte and Prince Louis to paint cinder blocks to support wooden planters at the engagement.

She told PEOPLE at the time, “He was determined to do it all by himself, and he managed to dig the whole paintbrush in, flick it up, and managed to cover quite a few of us in paint!” Laughing, she added, “He was doing a good job!”

Edwards added that Princess Charlotte kept an eye on her younger brother the entire time — much like she did two days prior during the coronation ceremony.

“She was advising him, obviously! ‘Don’t do that, Louis!’ — things like that,” Edwards said. She added of the three kids, “They were very relaxed and joining in, like normal kids. That was what was really nice about it.”

“Lou Bug” isn’t the only nickname that Princess Kate and Prince William, 42, are known to call their kids. In a 2019 video from Kensington Palace, the family of five attended the Chelsea Flower Show, and Prince William called out for his only daughter — but didn’t refer to her as Charlotte. Instead, he referred to her as “Mignonette,” a French word that means “small, sweet and delicate” or “cute.” As for Kate, she calls her daughter “Lottie,” and during a 2018 visit to Leicester, it was revealed that Prince George calls his dad “Pops.”

Following a planned abdominal surgery in January, Kate revealed in a much more somber video message on March 22 that she had been diagnosed with cancer. Nearly six months later, the news was much better for her Sept. 9 health update.

“The cancer journey is complex, scary and unpredictable for everyone, especially those closest to you,” Kate said, likely referring to her husband and three kids. “With humility, it also brings you face to face with your own vulnerabilities in a way you have never considered before, and with that, a new perspective on everything.”

She continued, “This time has, above all, reminded William and me to reflect and be grateful for the simple yet important things in life, which so many of us often take for granted. Of simply loving and being loved.”