An important part of "Santorianism" is that those "in command" must be absolutely faithful sexually in order to avoid corruption; otherwise they become self-serving, lose credibility and everything falls apart (and it usually does, at least in the Catholic Church). But this view also helps explain why "immutability" has become such an important argument. If homosexuality is a given fact of human nature, then the "tender little baby" part of heterosexual stability just has to deal with it. But if it can be "chosen", then gay people might be seen as being deliberately and knowingly destructive (the "stepping on toes" argument) of the emotional commitments of others. Surprisingly (or perhaps not) the gay establishment seems to go along with this view. I don't.
It seems that this idea says that patriarchal and fertile family heads will "nurture" someone like me but I am supposed to recognize my dependence on them and remain quiet and subservient, so they can get it up when the going gets tough. No, that's not a very acceptable idea.
Furthermore, it's not so much a matter that my private behavior or speech about the behavior harms others. It's more that if society and the legal system looks at it as OK, then the course of heterosexual marriage seems less remarkable and less interesting to "them". Therefore, it will tend to break down, as will other social ties that take care of people. That is how "they" seem to see it. It's an irony that the virtue of other men, insofar as I can perceive it visually, is actually important to me personally, and that corresponds to what we usually see as wanting "religious morality" to be applied to everyone.