Try thinking about this a different way.
Imagine, you told them. describe their reactions.
Now, Imagine you told them a week ago. How will they be reacting? How will it have affected you, your life and their behaviour?
I may be wrong, but I get the feeling that, they won't accept it, no matter what you say or how determined you are, they won't accept it, they will find a way to fit your life, as they do with everyone's, into their rather closed view of the world. You will continue having to live as you are now and be no happier.
If that is the case, then there really doesn't seem to be a lot of point in saying it to them. Kinda like telling your dog really.
As I said, I may be wrong.