The video depicts a man identified only as Yankel telling jokes to his off-camera friends and making up a fake back story about his friendship with the guard, who was on duty and dressed in the uniform of the Household Cavalry Regiment, the Daily Mail reported Wednesday.
The soldier was able to remain stone-faced while Yankel, who appears to be an Orthodox Jew, told stories about how they have known each other for "30 years" and how they went to school together in "Kensington."
The guard finally cracked a smile when Yankel mentioned how the guard was picked up from school by his mother every day until he was 20-years-old.
The guard's smile was met by cheers and celebratory dances from Yankel and his friends.
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