"Happy May Day," the couple's team wrote below the video Kate Middleton and Prince William are teasing their next project. On May 1, the Prince and Princess of Wales' office at Kensington Palace posted a mysterious new video to their social media accounts.

Princess Kate’s cancer diagnosis last year made the Prince and Princess of Wales “prioritize family and each other over everything else,” a source tells Vanity Fair. Now, with their three kids in tow,