In an apparent breach of royal protocol, US President Joe Biden left his sunglasses on during his meeting with Queen Elizabeth on Sunday.

The Windsor Castle meeting took place when the President and First Lady Jill Biden were in the UK for the G7 summit.

According to the Independent, quoting a former palace employee, as they attended the event hosted by the Queen, Biden did not remove his sunglasses.

Leaving your sunglasses when meeting the monarch, and therefore not making eye contact, is considered an insult.

The slip-up was a serious breach of royal protocol.

As Biden stood for a Guard of Honor at the castle and the American national anthem was played, Biden stood next to the 95-year old Queen with his hand on his chest with his sunglasses on.

Soon after, he and the First Lady joined the Queen for tea in the castle.

According to Newsweek, the Queen was not phased by Biden’s royal blunder. She was seen laughing several times with the president and his wife.

Biden reportedly had his shades on to shield his eyes from the harsh glare of the sun. Temperatures on Sunday in the UK topped out at 80 degrees Fahrenheit.

This is not the only faux pas that has happening in recent times during a presidential meeting with the Queen.

In 2019, former President Donald Trump famously misstepped when he placed a hand on the Queen’s back as he stood next to her during a presidential toast at a state banquet.

Touching the monarch is a longtime taboo that is strictly forbidden.

Former First Lady Michelle Obama also broke the protocol when she gave the Queen a hug during a 2012 meeting.