When I was scared out of my wits by something my kids told me (they are now 29, 32 and 35) my first reaction was the old "morality" thing. Five words out of my mouth later, and I realized how far I had put my foot into my mouth. The problem for me simply was that while I was very open to what my children wanted in regard to their lives, being scared or caught by serious surprise was a trap that made both of us miserable.
It takes a parent who is very secure in themselves to do the best job of parenting. I was doing my parenting as a single father for 15 years before my youngest daughter reached 21, and needed some counseling for things I was not doing my best at. The counselor told me simply, that I would never be able to do the best job of parenting that I could, but I would do the best job I knew how to do.

Put politely, I needed to learn more about the job in order to do it better!! Parents who stay stuck on the "morality" issue alone NEED to realize that with learning about the child and even the bigger world, they will see where really, their child is living the best part of their real goals.
A favorite passage that I learned from the book "The Prophet" by Kahlil Gibran goes "Your children are not
YOUR children, they are the sons and daughters of LIFE longing for itself, and though they come through you, the do not come from you --- You may house their bodies but not their souls". (Emphasis is mine.)
I have said this often to other parents who know nothing about my Trans issues, but "The worst thing is not finding out your child is gay, lesbian or Trans!! The worst thing will be to find out they are dead by way of suicide or murder because they were GL or Trans."