For a bit of context,

On the 1st of December I went to a concert of Sabaton in Amsterdam.

Every single time a song ended,

The whole crowd including myself started yelling:

"Broek uit, op je hoofd!"

Which means: " pants of, on your head!"

Eventually when they played their last song "Masters of the world"

Joakim Brodén (the lead singer)

Put a pair of pants on his head =]

And that was awesome!!