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.

Prince William and Kate Middleton showed a rare public display of affection as the royal couple marked Valentine's Day with a kiss.