I went to the Mardi Gras in Australia a few years ago and there were so many guys there dressed up as women (not girls, women) who were there with their other halves. I spoke to one guy called dave in a stunning sparkly ball gown and he told me that he only dressed up and went out of the house this one time a year and that she came to support him.
From talking to her it wasn't really her bag of chips but 'its better than golf'
I think it would be good if you could find a place, annually, where you could go and support him in this venture. I can understand now that the kids have grown up he wants to explore going out as a woman a bit more. I would want to have a few different converstqaions if it were my fella.
I would want to know:
Do you want to BE a woman? Or do you want to be a man dressed as a woman?
Do you want to do this regularly or all the time?
Would you be happy with say once a month doing a role play in the home and annually going to a party outside the home?
Because actually, whether YOU like it or not, if its something that he wants to do then that should be something you find a way to fulfil for him as a couple. I agree with a PP that the whole 'adult baby, wanting to be a little girl' thing is disturbing for different reasons and I would take exception to that.
But men wearing womens clothing? Quite common on the Sunday morning of a music festival, look at Paul o Grady for role-play and Eddie Izzard just for a guy who likes womens clothing.
Of course you are entitled to your feelings on it, but perhaps not to let your feelings on it mean that he cannot explore his own creativity in this respects.