A fair and equitable approach to...polygamy?

I thought of this idea yesterday when I read that Stephen Harper decided to go all "OMG, but if they legalize same-sex marriage then they'll legalize polygamy!!!!!111!!!1eleven!!" (Never mind that if you Google the words slippery slope it returns information about logical fallacies...) I didn't blog about it since I didn't want to dignify his comments with a blog entry, but today both CBC'S The Current and Prime Minister Paul Martin chose to comment on it, so it's not like my blog is loud enough to add to the din...

It occurred to me that the idea of polygamy being legal doesn't bother me at all. I find the idea squicky and certainly wouldn't want to live that way myself, and I wouldn't march and write letters in support of it or anything, but I simply don't care one way or another of other people decide to do it.

However, the existing models for polygamy, being a tad old-fashioned, aren't exactly equally fair to everyone involved. So I invented a way to update polygamous marriage for the 21st century.

All you have to do is invoke one simple rule: each person in the marriage must marry every other person in the marriage by taking separate vows for each person.

So suppose A and B want to get married. At the ceremony:

A vows to love and take care of B forever
B vows to love and take care of A forever

Some time passes, and A gets the idea of also marrying C. Suppose B consents. So at the ceremony:

A vows to love and take care of C forever
C vows to love and take care of A forever
B vows to love and take care of C forever
C vows to love and take care of B forever
And, of course, A and B could renew their vows to each other if they choose to do so.

If A dies, B and C are still married to each other. All existing married spouses are treated as a unit, so if one person wants a divorce, they have to divorce ALL of their spouses - you can't divorce just one or two.

There you go, Mr. Harper, since you seem so eager to start a dialogue about polygamy, you now have a viable model for the 21st century. Now you just have to figure out how it would work WRT taxes, insurance, next-of-kin etc.