Here's an excellent article by Archbishop Chaput on a Boulder, CO, Catholic school that has decided not to continue enrolling the children "of" (I use the term advisedly) two lesbian women.
The Archbishop makes a number of good points, and I want to draw out one of these points more explicitly in response to the "what about all the other sinners" objection.
The problem is not with allowing the children of sinners to attend a Catholic school! Obviously not, or there would be no children in the school. Nor is the problem even with children attending the school whose parents do, in fact, reject Catholic teaching on this point or the other--say, on the use of birth control. While I would support a Catholic school's right to refuse to enroll children whose parents are not willing to swear that they do not use birth control, the importance of such a policy for a school's Catholic identity is nothing like the importance of not enrolling the children "of" homosexual couples. The Archbishop expresses the matter rather delicately:
If parents don’t respect the beliefs of the Church, or live in a manner that openly rejects those beliefs, then partnering with those parents becomes very difficult, if not impossible. It also places unfair stress on the children, who find themselves caught in the middle, and on their teachers, who have an obligation to teach the authentic faith of the Church.
Most parents who send their children to Catholic schools want an environment where the Catholic faith is fully taught and practiced. That simply can’t be done if teachers need to worry about wounding the feelings of their students or about alienating students from their parents. That isn’t fair to anyone—including the wider school community.
Let's translate that into practical terms, giving imaginary names to the people involved: Every single time Mrs. Jones, the first-grade teacher, refers to one of the two lesbians who consider themselves to be little Betsy's "mothers," the teacher has to make a decision. What does she call these women? They may both have adopted Betsy, or it may be that one woman is Betsy's biological mother (by artificial insemination) and the other woman has no parental relation to Betsy--either biological or legal. In either case, it is the Christian and Catholic position that the lesbian relationship is not even remotely like marriage and that Betsy does not have two parents in anything remotely like the sense in which a child has two parents when he has a mother and a father. Yet if Mrs. Jones calls Betsy's biological mother "your mother" and the other woman "your mother's friend," there will be a big blow-up, and Betsy (who has been told that she has two mommies) will be distressed. If Mrs. Jones insists (if Betsy gets sick) on treating one of the women as her mother and not the other, there will be a major problem. And the same for all the other parent-teacher interactions. If neither woman is Betsy's biological mother and both have adopted her, Mrs. Jones might choose (still trying not to give in to the myth of the "lesbian family") to refer to them both as "your adopted mothers" or "the ladies who take care of you" or something. Imagine the fuss that would cause. If, on the other hand, Mrs. Jones just gives in and goes along with the "Betsy has two mommies" meme, she is implying something to the other children in the class that is contrary to Catholic and Christian teaching.
Or consider the way in which the presence of Betsy and her "two mommies" puts difficulties in the way of the Christian parents whose children attend the school. At school programs and sports events, how do other parents speak to their own children of the lesbian couple? Do they call them "Betsy's mom" and "Betsy's other mom"? If they do not, if they explain the truth of the matter to their children in any terms at all, what do the children do when Betsy herself refers to the two women as her "mothers"? And in any event, the presence of the two lesbians at such events communicates to all and sundry the idea that the three of them constitute a family unit. The tacit acceptance by the school of this group as a family unit thus puts the homosexual agenda in the faces of Christian parents who chose the school to avoid exactly such things as the attempted normalization of the homosexual agenda.
The lesbian couple with the child in school attempts to force school personnel and other parents and families to affirm the homosexual agenda continually in word and in deed. If both women are invited to parent-teacher conferences, this affirms the status of their relationship as being similar to marriage. If Mrs. Jones refers to both women as "your mother," this affirms the status of the relationship as similar to marriage. This problem does not arise with heterosexual couples, not even with those who are divorced and remarried without annulments. It is far, far more of an affirmation of a perverse attempt to remold reality for the teacher to refer to a child as having “two mommies” than for the teacher to refer to a stepfather as “your dad” or even "your stepdad" and the biological mother as “your mom.” (For all that says about anything, the mother could be a remarried widow.)
The situation with the two lesbians is an attempt to co-opt the school for the homosexual agenda in a way that the school should not be a party to. Consider the implications for a situation like the one with Lisa Miller that I discussed here. Miller's former lesbian partner is claiming to be the child Isabella's mother and demanding full parental rights in law--at the moment, this involves her being granted full custody by a judge, though the custody order has not been enforced because Lisa and Isabella have disappeared. Suppose that the two women had stayed together longer before Lisa repented and got out of the relationship, and imagine that they had sent Isabella to, say, a Catholic preschool. Janet Jenkins, the lesbian ex-partner, would now be able to say, “The Catholic teachers at the Catholic preschool called me Isabella’s mother! What’s the matter with all the rest of you?”
Catholic and other Christian schools should not cooperate in sending that message.
The focus in the Colorado case should not be on whether some sin is such that it is legitimate to "punish" the children of the sinners by refusing to enroll them in a Catholic school. The focus, rather, should be on the way in which the school's normal activities will or will not be co-opted for the parents' blatant and aggressive promotion of a sin they are proud of. And by that measure, the enrollment of the children "of" homosexual couples is off the charts.