John Culhane, Professor of Law and Director of the Health Law Institute at Widener University School of Law and Elizabeth Marquardt of the Institute for American Values write in the Huffington Post:

When it comes to parenting, three's a crowd. SB 1476, the "Parent-Child Relationships" bill introduced by state senator Mark Leno, which seeks to clarify judges' ability to recognize more than two legal parents for a child, is well-intended but flawed. It has passed the senate and could reach the assembly floor this month. California legislators should not support this bill.

... And why stop at three? Senator Leno's bill places no limit on the number of possible parents. If three's a crowd, four or more is a mob.

...Prominent LGBT rights organizations have come out in support of this bill, but the issues it addresses are not limited to same-sex couples. For example, In Re M.C. would not have been different if already-pregnant Melissa had married a man. The ambiguity about who is the legal parent, the biological father or (in that case) the husband, would remain. And in either case, the court should make that decision.

Courts are dealing with complex and often tragic situations. The search for responsible adults can tempt judges into "discovering" additional parents. But the law should continue to use, and refine, more precise instruments to assist children without warping the sound "rule of two."