The reason why Meghan Markle wore flats on the beach.

There are only a few rules for the beach: 1. always wear sunscreen, 2. swim between the flags and 3. don’t bother trying to wear any footwear other than thongs because it doesn’t work.

It is this third rule that has us feeling very uncomfortable about photos of Prince Harry and Meghan Markle on South Melbourne Beach during their royal tour on Thursday.

You see the royal couple wore… shoes. Actual shoes.

Yeah.

It’s… awkward.

Harry was wearing black lace up shoes and his pants covered their top, but you just know that sand still made its way in and will be encased in both his shoes and socks forever and ever.

Meghan on the other hand... Oh, poor Meghan. She wore flat shoes and... well, see for yourself:

Nooooo.

Probably the most uncomfortable moment of her life, tbh.

Imagine hopping in the car or taking those shoes off at the end of the day and... oh look, you've now got your own personal beach. ¯\_(ツ)_/¯

We're sure the Duke and Duchess would have rocked a pair of thongs, but alas, royal etiquette says no to such practical footwear.

Etiquette expert William Hanson told Harper's Bazaar open-toed shoes are considered informal footwear - and yes, you'd think a beach was considered informal enough - but despite the location Meghan and Harry were on an official engagement and therefore required formal dress.

But while open-toed shoes are a no-no... sometimes practicality prevails.

Meghan wore wedge heels to Bondi on Friday, where she and Harry took part in a "Fluro Friday" session by surfing community group OneWave to discuss mental health issues and interact with others enjoying yoga and surfing.

Thankfully, the couple learned from their mistake and took off their shoes and went barefoot on the beach.

Phewf.

Following their time at Bondi, day four of the royal tour also includes taking part in youth advocate program to discuss social justice and youth empowerment with students. The Prince will climb Sydney Harbour Bridge with Prime Minister Scott Morrison and Invictus Games competitors to raise the Invictus flag, and both the Duke and Duchess will meet with Opposition Leader Bill Shorten at Admiralty House and PM Morrison at Kirribilli House.