Because my native language is Danish, and "hej på dig" is a phrase that hasn't been used in Danish since the '60s, as it's been replaced with "hej med dig".
I did not read the story, and made the assumption based on the title alone.
Du siger noget. Its probably swedish though, since you can say "hej pa dig" there. (med den lille circel over a'et. Mit mobil keyboard har det ikke)
But not Norwegian, since it is "hei pa deg" there.
And replying to your newer comment didn't work for some reason.
The danish bits are to prove I speak your language, Dane.
