slippery slope

I've said before that the 'problem' with Prop 22 and other gay marriage legislation is that these types of laws open the door for 'polygamy,' 'incest,' and 'pedophilia.' Now, a recent posting from Newsweek suggests, at least to me, that social attitudes may be shifting towards greater acceptance of inter-family marriage, in addition to acceptance of gay marriage. I'm not sure how I feel about what appears to me to be a widening definition of marriage (and, by extension, of romantic love, I guess). Growing up, I didn't have much exposure to alternate versions of a "happy family," but I know that part of the reason I like About a Boy so much (aside from the irreverent wit, of course), is Marcus's realization that, in strong relationships (of any kind, maybe), "You need a backup. If you're only two people, and someone drops off the edge...then you're on your own. Two isn't a large enough number. You need three, at least." Maybe in today's technologically-advanced (and technologically-accelerated, and technologically-dispersed) world, it's appropriate to celebrate any type of successful relationship.