Duchess Kate and Prince William share sweet moment during St. Patrick's Day outing

Duchess Kate and Prince William stepped out on St. Patrick's Day at a parade in London looking adorable as ever. And while Kate's blossoming baby bump, which looked perfect in an emerald green Catherine Walker coat dress, made headlines alone, there was also one another important moment that everyone missed.

It seems as if Kate and Wills are taking cue from Prince Harry and Meghan Markle in the PDA department. The royal couple did something extremely rare for a public appearance ... they touched!

William sweetly showed affection by placing his hand on his wife's back. And while it's not a sweet kiss or hug that we were all expecting ... it's something (and more than we've ever gotten from the two before!).

If you recall, the world took notice of Meghan and Harry's PDA shortly after their engagement reveal. Meghan comforted a nervous-looking Harry by frequently rubbing the small of his back during their photo call and BBC interview. During their World AIDS Day outing, Meghan and Harry couldn't stop holding hands.

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This PDA is a shock to many considering Queen Elizabeth actually set a precedent of keeping one's hands to themselves during official royal engagements. But if there's anything we've learned in the past couple of months since Harry and Meghan's engagement, it's that they're not an ordinary couple who follows the rules.

We were hoping that some of Meghan and Harry's loving PDA would rub off on Kate and William ... and we were right!