Emmanuel Macron's wife had defiant five-word comment after his parents questioned couple's age gap when he was 15

Emmanuel Macron's wife Brigitte had quite the defiant five-word comment after his parents questioned the couple's age gap when he was just a teenager.

Over the weekend (25 May), the 47-year-old French president and his missus, 72, kicked off their South-East Asia tour starting with Hanoi in Vietnam.

Footage from the Associated Press shows Macron standing by the plane's exit as workers opened the door, at which point a hand believed to be Brigitte's suddenly comes into view and appears to 'slap' his face.

Seconds later, Brigitte walks out behind him and the pair descend the stairs onto the runway.

Needless to say, the footage has sent the internet into a right frenzy, with a body language expert and lip reader also getting involved to share their thoughts on the now-viral incident.

Emmanuel Macron and his wife, Brigitte, have gone viral this week after she allegedly 'slapped' him (Christian Liewig - Corbis/Corbis via Getty Images)

And, amidst all the noise online of social media users speculating over the nature of the 'slap', Gen Z have been left pretty shocked after realising how Macron even met Brigitte in the first place, given their near 25-year age-gap.

Macron was just 15 when he met Madame Auziere, who was his 39-year-old teacher at the time, at Lycee La Providence in Amiens in 1993.

Also, Brigitte was actually already married to banker André-Louis Auzière, with whom she shares three children. Her eldest daughter, Laurence, was even in the same class as Macron.

According a timeline on their relationship by Sky News, the pair defied Emmanuel's parents, who told her to stay away from their son until he became 18.

"I cannot promise you anything," Brigitte allegedly responded at the time.

After the news of Macron and Brigitte's blossoming romance came to light, and caused a scandal in the province, the teen's parents sent the-then-17-year-old to Paris to attend another school.

Macron was just 15 when he met his then-teacher Brigitte who was 39 at the time (NHAC NGUYEN/AFP via Getty Images)

However, that wasn't enough to keep the pair apart as Macron reportedly told Brigitte in 1995: "I will be back for you. Whatever you do, I will marry you."

Brigitte eventually married Macron, who was a civil servant in his late twenties at the time, in Le Touquet in 2007, after divorcing her ex-husband the previous year in 2006.

He was 29 and she was 54.

Macron has previously claimed the recent 'slap' exchange between himself and Brigitte may not have been what it seemed.

He later told reporters that they had simply been joking around, with France24 reporting he said: "We are horsing around and, really, joking with my wife."

Macron added that the incident had been massively overblown, saying: "It becomes a sort of geo-planetary catastrophe."

His office had also previously offered an explanation, echoing that the couple were just mucking about.

"It was a moment where the president and his wife were decompressing one last time before the start of the trip by horsing around," a statement said. "It’s a moment of complicity. It was all that was needed to give ammunition to the conspiracy theorists."