“Oh, that’s very kind. Never go home empty handed! That’s a crucial motto of being a parent,” Prince William said in a video shared by The Independent.

“That’s really kind of you. Thank you very much. We’ll do some practice together,” William continued. “See how many windows I can smash!” he added with a laugh.

The Princess of Wales announced in a Sept. 9 video message that she completed chemotherapy treatment, and her husband and kids joined her in the footage unprecedented for its intimacy of their private life.

“Those children look pretty happy with life,” a palace insider previously told PEOPLE about the Wales kids. “A lot of it is the stabilizing normality Kate brings — and that’s how she grew up. William absolutely loves it.”

Despite their royal roles — especially Prince George, who follows his father as second in the line of succession to the throne — Princess Kate works to ensure her children’s childhoods are as normal as possible.

“The last nine months have been incredibly tough for us as a family. Life as you know it canchange in an instant and we have had to find a way to navigate the stormy waters and road unknown,” the Princess of Wales said in part.

Princess Kate said that she looked forward to “a few more public engagements in the coming months when I can,” and joined Prince William for an unannounced visit to Southport on Oct. 10.