And, given the murky sexual libertarianism of SCOTUS, there is absolutely no argument beyond “EW!” to prevent trampling down this taboo like all the others. When consent is the sole criterion of the good, who the hell are you to burden two (or more) free souls with your bourgeois morality?
What will make or break this new frontier in the sexual libertine movement will be money. If you can generate a big enough donor base to make the case for the wounded oppression of these Forbidden Lovers, then eventually there will be more Obergefallout on behalf of incest. I’m skeptical the money is there for these people. But money is the only barrier against advancing the logic of our cultural dynamic.
And note that, yet again, what this means is the power of the strong over the weak. If you think that, in such relationships, the child holds equal power, you will be an excellent tool and apologist for slave culture we are building.