Is there something wrong with me bringing up the fact that if the SCOTUS were to affirm SSM there would not be a legal argument against poly-amorous relationship? And, if so, who are you to tell me what subject I can discuss on this or any other forum?
As is your case, what I believe and what the law/s read are two separate issues. What I believe is that
incest piles the norms and statuses associated with romantic-sexual relationships on top of the norms and statuses associated with family relationships. T
hese two sets of norms and statuses are in deep tension which tends to damage the integrity of those family relationships.
Here is the liberal gay rights supporter William Saletan making this argument, and here is the conservative gay rights opponent Matthew J. Franck echoing him and expanding on it.