Not exactly DenNor, but I have this strong strong headcanon that the Nordics (or maybe just Sweden, Norway, and Denmark) will call each other these really over-the-top insults from time to time. Like, insanely over the top. Like Norway might call Sweden a "meatball-loving, ikea fucker" or something like that. The best part is, if someone is feeling upset (*cough* Denmark *cough cough*) Norway might come up with a supremely stupid insult to make him laugh.
“Oh my god Denmark, you obnoxiously-coloured lego flavoured egg mcmuffin”