Because they already share legal kinship. They are already a family under the law.<quoted text>
Only in the context of procreation. Go read the rulings.
Skinner v. Oklahoma (1942):
Oklahoma deprives certain individuals of a right which is basic to the perpetuation of a race the right to have offspring. and We are dealing here with legislation which involves one of the basic civil rights of man. Marriage and procreation are fundamental to the very existence and survival of the race.
Is there a compelling reason to not allow a father-son the same legal kinship that others are allowed?
I will never understand this fascination with incest that seems to exist only in the anti-marriage population. It seems like the fall-back argument when all else fails.
Can YOU explain it?