Written Norwegian and Danish are so similar that on the back of products that has a description in several languages, Norwegian and Danish are usually mixed together, and the few words that a written differently are separated with a /. So I love you would look like this on the back of a product:
SE (Swedish): Jag älskar dig. FI (Finnish): Minä rakastan sinua. DK/NO: Jeg elsker dig/deg.
Ive never thought about it before, but it was pointed out to me a few weeks ago that DK/NO looks like someone was writing a paring, like Harry/Draco. I havent been able to unsee it since.