I found a link to this article on the HMS blog thanks to Kevin Miller. Basically, a threesome is suing for the right to all be considered parents of a child.
Even if I were not a Christian, I would see a practical problem with this:
1. Babies are produced by a union with an egg and a sperm. Science will tell you that one man and one woman unite. How can a child have three parents?
2. By having everyone and their brother come and sue to have their “marriage” legally blessed, we will be faced with an endless series of court cases, consuming time that could be used for more important things. Even if we gave these relationships legal status, we would then be faced with an endless series of divorce cases in divorce courts because inevitably many of these “loving” relationships will break up.
3. A group of people might then decide to all get together and form a nationwide marriage chain until everyone in the whole country was married to everyone else. Why not?