Are "pagans" unfit parents?

My friend Eugene Volokh has a post up, over at his blog, about a recent decision, Dexter v. Dexter, in which (quoting Eugene) a "mother's open paganism [is] treated as [a] reason to deny her custody."  Prof. Volokh writes:

[T]he reference to mother's paganism — and the view that pagans may be denied custody because their open practices risk "exposing such lifestyle to [their] child[ren]" — strikes me as a clear First Amendment violation.

It seems to me that her bisexuality should likewise be none of the court's business; nor should her sado-masochism, unless there's some specific evidence that the practices are physically harmful to her and thus indirectly to the child (evidence that judgment, the magistrate's findings, and the appeals court decision never even hinted at).

I wrote a short article, several years ago, about parents' religious beliefs and child-custody matters, basically agreeing with Eugene's approach (i.e., an approach under which the content of parents' religious beliefs should not be regarded as a "harm" to children).  But, I wonder if I was wrong?  Putting aside the caselaw, surely it is the case that some parents' religious beliefs and practices are harmful to children?  Or, can we not say this anymore?