User blog comment:Swordbirth18/Incestous relationship/@comment-209.140.235.254-20160220193548

I think the main thing that gets overlooked when people talk about this on the internet is that many of these "relationships are actually just sexual abuse involving an authority figure and a victim (parent on child, older sibling on younger sibling, etc.).  In those situations it's always for the best for the law to intervene so that the predator can be removed from society and the victim can receive treatment (same as in any rape scenario).