@Kllick Bad idea as Lemon have said elder sisters usually abuse or at least mean to their younger siblings. I also read some article where some girls make their younger brother crossdress in japan.
@Jeirien First time hearing it. Now that's fun because I can do something a bit nasty to dominate them. I mean, I'm an S. The more sadist my target the more pleasure I get.
@boag how? Did she magically extend her neck and dived it underwater fitting it into the small gap between their bodies and suck him off under water only coming up to breath?
@Kllick@Jeirien I highly doubt that shit is common in Japan. I am sure it has the same rate as anywhere else in the world
Basically, if you're raised in close proximity, up to around 6-7 yrs of age, then regardless of blood relation, you identify those individuals around you as family, and are repulsed at the thought of sexual relations with them.
Females are more sensitive to this effect than males.