Incest is, despite its taboo nature in most societies, actually a pretty popular convention in both romantic fiction and works of a more erotic bent, in everything from period or fantasy pieces to series taking place in places like modern day Japan. Still, the most common configuration in these fictions are the pairing of siblings. Perhaps this is because of the usual lack of age difference and power dynamic that exists in child/adult relative pairings, though this is not always the case. Because of this, a sexual or romantic relationship between siblings can almost seem, well, romantic in the right light. Of course, more often than not, there's a dark side under the veneer of forbidden love. This meme is for those who would like to play out that, either the darkness or the light - or both. HOW TO PLAY