I'm not sure I'd be interested in having more than one spouse at a time, myself. As my wife knows (and approves), I am a devout romantic and regularly develop mad crushes on various women despite the fact that I'm married; but I haven't figured out a good way to deal with that and don't want to leave or betray the spouse that I have.
However, since adultery is almost universally legal, it seems ironic to outlaw attempts to legitimize polyandry or polygamy. If all the parties consent, why not? But no,  I'm  not going to do that.

-Joe-