Warning to tourists: Never mess with the Queen's Guard.
We've already seen a little girl get slapped in the face (albeit by mistake) and another being barged out of the way
But this tourist pushed his luck too far, prodding the soldier until the soldier lost his patience.
The man can be seen marching alongside the soldier, following him up and down and reaching out to touch him on the shoulder.
It was then that the guard, dressed in the traditional bearskin hat and red coat, whipped round and pointed the bayonet -tipped gun in the man's face.
The guard can also be heard to shout: "Step back from the Queen's Guard!" at which point the man is seen jumping away in shock.
The Queen's Guard (or King's Guard if a male monarch is in power) are charged with guarding the official royal residences of the United Kingdom.
Despite popular belief, the guards are not just for ceremonial purposes, they are actually fully operating soldiers.
In the capital, the guards can be seen at Buckingham Palace, St James's Palace and the Tower of London.
Changing the Guard at Buckingham Palace takes places at 11.30am each day and has become a popular tourist attraction.
Just last week another tourist was subject to the power of the Queen's Guard while absentmindedly strolling through one of London's parks.
The guardsmen were on the move outside London's Buckingham Palace when the tourist was barged out of the way.
According to the Mail Online, the tourist in question was Gerry Weatherhead, a retired RAF engineer.
He said: "As a former military man myself I'm more embarrassed than anything else - but no one was hurt and there was no harm done. It's quite funny really!"
The Guards were also forced into the spotlight in April when during the Changing the Guards ceremony one poor soldier lost his footing on a shiny metal plate on the floor.
The embarrassed soldier quickly scrambled to his feet and maintained his composure throughout but, unsurprisingly the video went viral almost immediately.
Meanwhile in September last year, a dancing guardsman put on an unusual show outside Buckingham Palace after breaking strict rules by performing ballet-style pirouettes in front of the royal residence.
Bits of Buckingham Palace keep falling off - Queen might need to move out
Pirouetting guardsman faces three weeks in military prison
Tourist sparks security alert at Windsor Castle