Is sexual relationship between two consenting adult siblings ethically okay and should it be legal? It's an interesting ethical problem because there are so many complicated dimensions and it could go either way. I think generally when it comes to social issues our society seems to head in a right direction, people are becoming more tolerant of people who choose differently and so on, but incest between siblings seems to become maybe more taboo even though there are some rational justifications you could make for it.

Some have made parallels to homosexuality as in it doesn't directly hurt either of the sides of this kind of relationship. There are social problems, I mean if I got to choose I wouldn't like any of my relatives to get together because that would evoke feelings of disgust, unnecessary drama and awkwardness, but I think I would have said the same thing about homosexuality 70 years ago. In theory inbreeding shouldn't be a problem, but in practice it probably is. Even though contraception is widespread in this day and age, if large number of siblings have sex with each other, some of them will inevitably end up having kids.

German ethics council decided that it should be legal because it's a person's fundamental right and people's right to self-determination is more important than the protection of your family.