People are just realizing how French president Macron and his wife first met amid viral 'slap' incident

A new biography of French president Emmanuel Macron delves further into how he first met Brigitte and what happened when his parents found out.

On Sunday (May 25), footage of Brigitte Macron and President Emmanuel Macron went viral showing the First Lady of France seemingly pushing or slapping the leader after they touched down in Hanoi, Vietnam.

A lip reader weighed in reviewing the exchange as pretty frosty, however, Macron later spoke out about the clip, stressing the pair were 'joking'.

And the incident has led to many discovering how Macron - aged 47 - and 72-year-old Brigitte - nee Trogneux - first got together.

The couple first met in 1993 when the now-president was 15 years old and Brigitte was 39 years old.

Emmanuel Macron appeared to be 'slapped' by his wife (AP Photo/Hau Dinh via Alamy)

How Emmanuel Macron and Brigitte Trogneux first met

Macron was a student at a private secondary school called La Providence, located in Amiens, northern France and Brigitte was a teacher at the very same school.

Trogneux reportedly taught French lessons as well as drama classes - the latter in which she is said to have met Macron.

At the time, Brigitte was married to banker Andre Auziere - with whom she shares three children: Sebastien, Laurence and Tiphaine.

And according to writer Anne Fulda - who's written a biography on Macron's life titled Emmanuel Macron: A Perfect Young Man - Macron's parents initially believed he was dating one of Brigitte's children.

The pair met when Macron was at secondary school (LUDOVIC MARIN/AFP via Getty Images)

What Macron's parents have said about discovering his relationship with Trogneux

Macron's parents told Fulda they found out their son was actually engaging in an affair with Brigitte through a family friend.

His mother, Francoise Nogues-Macron, said, as quoted by The Independent: "We just couldn’t believe it. What is clear is that when Emmanuel met Brigitte, we couldn’t just say, ‘That’s great’."

His father, Jean-Michel Macron, echoed: "When Emmanuel met Brigitte, we certainly did not say, ‘How wonderful!'"

They ultimately decided to pull Macron out of the secondary school, however, Nogues-Macron noted ultimately 'what mattered' most to her was her son was 'alive' and 'there weren't any problems'.

Although, she did reportedly turn round to Brigitte and point out Macron would ultimately 'not have children' if they stayed together and she'd already 'had [her] life'.

When allegedly warned by Macron's parents to leave their son alone until he was at least 18, she allegedly replied: "I cannot promise you anything."

And Brigitte has spoken out publicly about the relationship too.

Macron and Brigitte have both publicly addressed various rumors (NHAC NGUYEN/POOL/AFP via Getty Images)

What Trogneux has said about her relationship with Macron

In an interview with Elle France magazine in 2017, Brigitte said her and Macron's romance 'unfolded very slowly'.

Macron went off to Lycee Henri IV in Paris to finish his studies but reportedly vowed to come back and marry Brigitte.

She said: "The great distances that separated us physically until 2007. But we wrote to each other all the time during that period.

"It all unfolded very slowly. I gradually brought my family to realise that. Emmanuel gradually brought his family to realise that."

In 2007, the pair married when Macron was 29 and Brigitte 54.

And to those who highlight the over 20-year age gap between them?

Well, she said the pair have made it a 'joke between' themselves and 'anything anyone might say' is ultimately 'just a big nothing'.