Something I learnt from Germany in my recent trip there:
In Germany, a Bratkartoffel relationship refers to a relationship based purely on sex.
Brat = fried
Kartoffel = potato
Apparently, it’s so-named because fried potatoes are so common in Germany, thus alluding to the casual nature and the frequent occurence of such relationships in society.
Interesting. And I suppose it’s a good thing (or not?) I don’t like eating potatoes! ;p