I wouldn't care.. I think it's weird how women can wear jeans and trousers nowadays and nobody bats an eye but if a guy does the same thing with traditional female clothes it's freaking weird. I'm against all types of gender double standards so I say go for it.
I like to cd once in a while. It is a fetish of mine. I keep it to myself. I do it in private and do not go out. It is something I do for my own pleasure. I am not into showing off for other people. I find cd is one of the least accepted fetishes and something a lot of people have a problem with which is why I have no desire to share it.
It is their life, and everyone has a right to war what is comfortable for them.
I'd consider it to be none of my business, and as long as he didn't want to include me in his activities I'd be fine with it; but if he wanted to go out with me while dressed as a girl, that's not something I'd be comfortable with.