It doesn't have to be random and independent. If neither sibling has power over the other (any more than any other couple), one proposes it, and the other accepts despite never having thought about it before and perhaps after thinking about it after, there's still no problem, that's literally how consent works.
Right but again it's a question of when it was brought up and how. If someone is taught by their sibling from a young age that incest is cool and good, that's not ok with me.
It doesn't have to be random and independent. If neither sibling has power over the other (any more than any other couple), one proposes it, and the other accepts despite never having thought about it before and perhaps after thinking about it after, there's still no problem, that's literally how consent works.
Right but again it's a question of when it was brought up and how. If someone is taught by their sibling from a young age that incest is cool and good, that's not ok with me.