Etiquette experts say he also made a faux pas by clinking his glass against the royal's, though she smiled throughout the festivities.
The first lady wore a Dolce & Gabbana dress with navy trim and a matching hat to visit Buckingham Palace.
The Queen is set to meet Donald Trump for a second time during his state visit to the UK next week. And while President Trump may be looking forward to his royal meeting, he won’t be staying at Buckingham Palace due to building works - nor will he be taken on a carriage procession, at the insistence of US security services. The Queen is set for one of her easiest state visits , according to royal biographer Robert Hardman - but it is certainly not her first meeting with a US President. Read more from Yahoo News UK: Trump says he might meet Boris and Farage during state visit More than 750k Europeans have applied to stay in UK after Brexit Unseen messages show how Nazis fell for D-Day plan In fact, Her Majesty has met with 12 Presidents, including Trump, during her time as Queen. One of those was in fact when she was still a mere princess - but came three months before she became Queen. Here is the roll call of all the Presidents the Queen has had the pleasure of getting to know over the years...
Queen Elizabeth was joined by her husband, Prince Philip, while stepping out for the Order of Merit service at Windsor Castle.
Astrologer Chris Love takes us through the astrology of the new royal baby, helping determine what we can expect from Prince Harry and Meghan's first born.
Michelle Obama is still answering for the time she supposedly breached royalprotocol by hugging Queen Elizabeth at Buckingham Palace in 2009