Man succeeds in making Royal Guard crack a smile and people fear he may lose his job

Keeping a straight face can be hard at the best of times, but now people are fearing that a royal guard will lose his job after giggling whilst working.

The clip opens with an unknown tourist claiming that he’d known the Royal Guard for over 30 years with the bemused soldier looking at the camera under his helmet.

The antics then quickly begin to escalate as the tourist jokes that the pair went to school together and even quips that they learnt marital arts together as children.

“He was never talkative, I remember in school, he just used to sit by himself,” teased the visitor.

“I was just this guy fooling around having fun,” he continued, adding: “You’d ask him questions and he’d just answer with his head."

The nearly four minute long clip continues as the American tourist continues to goad the officer with more fake stories of their time at school, even saying that he'd answer no to his name: "What's your name, no? Is that a name?"

"His mother always had to pick him up from school until he was twenty," yells the visitor as his friends roar with laughter.

Desperately trying to contain, the guard looks to his colleagues for help but struggles to keep a straight face amid the contagious laugh.

But the guard can't hold his stoic expression for long and breaks into a smile, shaking his head slightly.

As the tourist and his friends fall about laughing, the poor guard still tries to keep a straight face and quietly chuckles as the visitors walk away in hysterics.

Most comments have been very sympathetic to the officer, with one kindhearted commenter stating that he had a ‘pretty great smile’.

One Redditor wrote: “From the first little twitch, you can see this is a battle he wouldn't win.”

“He gets redder until he can’t take no more,” wrote one viewer.

Others have commented on the poor officer going red as the video progresses, as he tries to remain professional.

The clip has proved so popular in fact that many people have called for a sub-reddit to be made of Royal Guards laughing.

They added that rules are so harsh that most royal guards won't ‘catch themselves if they collapse from heat, they have to just fall flat on their face’.