This is what happens when you harass the Queen's Guard
We can safely say that this is the last time that guy messes with one of the Queen's Guards.
After mimicking the soldier's walk and following him up and down, the tourist went too far and dared to touch the guard's shoulder.
That was the trigger.
The guard braced his rile, pointed it at the harasser and shouted: "Get back from the Queen's Guard!," making the young man jump out of his skin.
These guards have been less and less forgiving when it comes to annoying tourists, as we saw in a recent video where a spaced-out man gets run over by a group of walking soldiers.
More from AOL.com:
Twitter blasts homophobes for wanting to move to Canada
This invention lets you control your computer with a banana
These people are making art out of screen glitches