A request to Michael P. for views on the "plausibility" of an argument

in a recent post, Michael asked what a particular argument -- i.e., an argument that the facts recounted in a New York Times story describing the non-monogamous practices of some same-sex copules tell us something about the merits of the case for same-sex marriage -- would look like, and whether -- when presented -- it would be "plausible."

Rob Vischer then sketched out, in some detail, a possible argument.  Michael thanked Rob for his post, noting that it was "helpful."

Well, it's been a few days -- don't leave us hanging, Michael . . . is the argument sketched by Rob plausible?  If not, where and how does it misfire?  Let's keep the conversation going . . .