Melania Trump fans have new theory after spotting her unusual behaviour during Donald Trump’s latest appearance

US President Donald Trump attended Congress this week for the first time, and fans have come up with a theory about his wife after her 'bizarre' behaviour was spotted.

It all began on March 4 when Trump took to the stage to deliver a speech, which centred around immigration.

Having had a number of controversial moves since he took to office this year, the president’s latest target appears to be diversity, equity and inclusion, and the removal of illegal immigrants from the nation.

As well as covering his objectives, trade tariffs and the situation in Ukraine, Trump told Congress: "Within hours of taking the oath of office, I declared a national emergency on our southern border. And I deployed the US military and Border Patrol to repel the invasion of our country.

"And what a job they’ve done. As a result, illegal border crossings last month were by far the lowest ever recorded ever.

"They heard my words and they chose not to come. Much easier that way. In comparison, under Joe Biden, the worst president in American history, there were hundreds of thousands of illegal crossings a month and virtually all of them, including murderers, drug dealers, gang members, and people from mental institutions and insane asylums, were released into our country.

"Who would want to do that?"

Melania Trump was in the audience of husband Donald Trump's Congress speech about immigration and border control (Tom Williams/CQ-Roll Call, Inc via Getty Images)

While First Lady Melania attended the address alongside their family members, her demeanour was immortalised by fans who quickly screenshotted a key moment which they believe shows how she really feels about her husband and his words.

This theory stemmed from the way that the first lady and the president acted before they attended the event, as they believe that Melania was uncomfortable whilst holding her husband’s hand as they left the White House.

Inside the chamber, after he took another jab at Joe Biden and talked about American border security, Trump’s standing ovation was out of place around his wife… who remained seated.

On social media, fans speculated that she’s ‘not that much into him’ and she is ‘miserable’, with one person writing: “Why doesn’t Melania stand up for her man?”

Another commented: “What goes through her head looking at Trump? Clear she not that much into him. A mystery.”

Someone else speculated: “Melania Trump didn't look too enthused when Donald Trump entered the House chamber for his joint session address of Congress. She looks miserable.”

Melania attended her husband's Congress speech, but didn't stand up during the standing ovation (Fox 13)

While Trump did go on to acknowledge his wife’s contributions to ‘foster care’ and ‘community’, fans were set on her refusal to stand up as being a clear sign that all is not well with the couple.

A body language expert has also spoken out about her behaviour.

Truthplane's Mark Bowden analysed Melania's body language for Sportsbook Review and told Tyla: "Melania did not stand alongside all the upper gallery and the Trump supporters below her in the house when Trump talked of his mass deportation initiative. Could this have been a signal that some of his ideas do not fit with her view?

"Certainly, she made no facial signals of disgust or disdain as she remained singularly seated.

"Nevertheless, given that her own parents' US citizenship is due to the 'chain migration' process that Trump and his supporters have publicly denounced, it seems fair to assume she may be wanting to be seen as taking a stand - or seat - around that issue."