[[[The key word here is “consenting”, i.e. they want to do it.]]]
Exactly. Some people will want to do polygamy even if Slate writers do not. Recently a man in South Korea officially married his blue pillow. Not every man will want to do that. But the fact that the man could create his own pillow-marriage will erode the traditional male-female definition of marriage even further.
people sleep around and shack up all the time, what is stupid is asking the state (ie: society) to approve of it