Putting aside the potential for horrible side effects of offspring, I don't think an incestuous relationship can be 100% consensual.
It is generally considered morally wrong, or at least a seriously dangerous grey area, for two individuals with one in a position of power over the other to have a relationship. This goes for psychologists/patients, teachers/students, bosses/employees, and I believe it would extend to parents/children and even between siblings since there is always an order of authority that comes with age.
I don't think I have to explain why, but in short it's because the position of authority means there's too much potential for a "consensual" relationship to be the person in the position of lower power simply obeying the person in the position of higher power, or being convinced that it's what they want when it's just abuse from higher up.
The whole thing is ridiculously murky, and the laws and social mores in this case are there to protect the individual who is most in danger of being abused just as with other higher power/lower power relationships.
It is generally considered morally wrong, or at least a seriously dangerous grey area, for two individuals with one in a position of power over the other to have a relationship. This goes for psychologists/patients, teachers/students, bosses/employees, and I believe it would extend to parents/children and even between siblings since there is always an order of authority that comes with age.
I don't think I have to explain why, but in short it's because the position of authority means there's too much potential for a "consensual" relationship to be the person in the position of lower power simply obeying the person in the position of higher power, or being convinced that it's what they want when it's just abuse from higher up.
The whole thing is ridiculously murky, and the laws and social mores in this case are there to protect the individual who is most in danger of being abused just as with other higher power/lower power relationships.