You mean, like a marriage between a person and a non-human animal? Or a marriage between a person and a piece of furniture?Those citizens involved in any "marriage" which is different than other "marriages".
Does it violate "marriage equality" if people aren't allowed to engage in such marriages? Is that your argument?
Even in those countries where polygamy is given legal recognition, each marriage is still between only two persons.Make your case that a marriage can ONLY be two persons regardless of gender
I guess you missed that.
Maybe you don't know what "polygamy" means.