William and Kate shared the photo on their joint Instagram account, @princeandprincessofwales. On her own newly-launched Instagram account, Meghan, the Duchess of Sussex, shared a photo Friday of herself kissing Prince Harry along with a Valentine's Day message.

Prince William and Prince Harry are both fathers now, but once upon a time they were little boys growing up with one of the most famous mothers in the world. Princess Diana raised her sons with a strong sense of what it means to give back, and today, Harry and William have carried that tradition on to their children.

Meghan's post says she's "missing" her Valentine as Harry works at The Invictus Games, while William and Kate share a poignant picture with a heart emoji.