Is there a regional animosity between the Nordic countries?

Do they look down on each other as inferior? Is it more of a sibling rivalry? Is it just joking at the expense of a different culture?

I ask because I have seen literature that alludes to it and I had a Danish realtor who could not say anything nice about the Swedish; not sure what she did say because she said it in Danish but it was said very quickly and with great feeling. I asked her once and she said “The Swedes are swine! And the Norwegian are no better!” Was this just a personal affront or is it a more pervasive attitude?