I told my girlfriend that I sometimes crossdress. I wanted her to know so if she had a problem with it we could figure it out early in the relationship. Her reaction was to say that she thinks she is fine with that. It was better that I had told her than it being a secret that she stumbled across one day.
The topic comes up ocassionally and I answer truthfully. She has not seen me dressed but she asked if I would like to go shopping with her when we wnt on vaction together. She though I might like to go and get some ideas for myself. So far so good.

