Is he calling her an adorable nickname or something else? 

By Kimberly Truong
Updated May 22, 2019 @ 2:00 pm

On Monday, the Kensington Royal Instagram account posted a sweet video of Prince William, Kate Middleton, and their three children, Prince George, Princess Charlotte, and Prince Louis. And while the video included Prince George giving Kate's Chelsea Flower garden a rating of "20 out of 10," that's not what has people talking.

After that cute moment, Prince William turns to Charlotte and utters some syllables that have the internet stumped.

Watch the moment yourself, just before he asks her to push him on the swing.

One theory people have is that Prince William was calling her by a nickname: "Mignonette."

Other people, however heard something different, and think he's saying, "have you been on here?"

Princess Charlotte already has a very British nickname (Lottie), but it's not out of the realm of possibility that she'd have another one, too.

We'll leave it up to you to theorize what he's actually saying.