incest pregnancy endangers the child
if you want to argue siblings should be allowed to marry if they are not going to procreate, that be fine by me but it has nothing to do with gay marriage, it also has nothing to do with discrimination since nobody can marry there siblings give or take the distance of the relationship
the discussion was about discrimination and trying to relates incest to the not granting gays equal rights. that analogy totally fails and you post didnt change that
incest and allowing gays to marry are nothing alike.
d=fighting for or against them are not the same fight/arguments and never will be