Kate Middleton shares a sweet bond with her son, Prince Louis.

Middleton is very hands-on when it comes to her kids. The Duchess of Cambridge has enrolled her youngest child to weekly Monkey Music sessions, Express reported.

Each session costs $16 and moms are asked to join the activities with their kids. Middleton and the other mothers are asked to sing and dance with their babies. However, for security reasons, the one attended by Prince William’s wife and son cannot be revealed.

“Trusted by parents since 1992, there are 4-stages of classes, tailored specifically to the needs of babies, toddlers and pre-school children between 3 months and 4 years of age,” the Monkey Music website states.

According to the site, the children learn 500 songs during the program. Prince Louis made his balcony debut last June when he joined his parents Prince William and Middleton, siblings Prince George and Princess Charlotte, and the rest of the members of the royal family for Trooping the Colour. At the event, Prince Louis caught the attention of the public due to his grumpy face which many found adorable and funny.

Due to Prince Louis’ grumpy face, he was called the “boss baby.” At the same event, Princess Charlotte and Prince Louis were spotted showing off their royal wave.

Royal fans found Princess Charlotte and Prince Louis cute and adorable as they looked through the window. Prince Louis was so energetic when he waved so fast at the crowd. Some theorized that Princess Charlotte was teaching her younger brother her remarkable royal wave.

“Charlotte teaching Louis how to wave. Charlotte is an expert waver,” one royal fan commented.

Prince Louis has won the hearts of the royals fans that some of them wonder where Prince William and Middleton’s youngest son is as they have not seen him since June and they are already missing him.

“I can’t wait to see prince louis aka boss baby again!” one netizen wrote.

Kate Middleton, Prince Louis
Prince Louis is learning how to do the royal wave, according to Kate Middleton. Pictured: Middleton, Prince Louis departs the Lindo Wing with her new born son Prince Louis of Cambridge at St Mary's Hospital on April 23, 2018 in London, England. Getty Images/Chris Jackson