Semi-incest is a thing in Western culture, it must be pointed out. Like there's a huge stepsister thing going on. It's obviously a lot less weird to fuck your stepsister than your actual sister, but it's weird that this kink exists really. Most stepsisters are not hot and the relationship is usually more like sister/brother than friends, so I don't really know who's into that except for the few people who happen to have a really hot stepsister. Maybe that's for people who are into incest but are in denial so subconsciously seek out more palatable entertainment.