I believe it is important to tell your wife or SO about your cross dressing. I feel dishonest if I keep a secret of that magnitude from her. However, I have decided not to allow my future wife and/or SO see me en femme. Here's how I got there:
I dressed in front of my ex-wife a couple of times, and I dressed in front of my last girlfriend a few times. In both situations I felt a definite change in the relationship immediately thereafter. It was as if I had thrown a switch. Things were never quite the same after that, and I don't mean in a good way. I think some women feel as if their femininity or status in the relationship is threatened when they see you en femme. Cross dressing is very much like having an affair with another woman. The woman is part of you, but it still is infidelity in a way.
In the future, I will let them know about Carrie, but just keep her clothes in the closet when the real woman of the house is around. If your SO ASKS to see your alter ego, maybe it would be a different matter.
What do you think?