Sounds like rather complicated issue you are involved right now.
I really think you should have a nice long chat with her about this matter. It could be that she's just simply afraid of losing the "man" she once married. If she avoids the topic you can do it the same way she did and write a letter about the feelings you have about this matter. There has to be a way for you both to cope with this in a way that it will not harm your family or your lives in anyway. She did buy you some panties in the beginning and didn't have a problem with you wearing them as long as the girls didn't find out about it.
Take some time to think about your own feelings and write them down. This way you can give them to her and she won't really be able to "avoid" the topic. If she does, I don't think she deserves to be with you at all. No matter what the issues is it should never be ignored by one side. A relationship always involves two people and compromises have to be done in some cases but it's not a compromise if you have to give up on something you like to do.
Everyone needs something to keep themselves balanced. Be it reading a book, taking pictures or dressing into female clothes. If you can't have something to relax yourself your life won't be all that nice in the end. I really hope your wife sees into this matter as I truly think that no marriage should be broken because of something like this. Changing a sex is another matter but you have no plans of doing this so I really don't see a reason why she would have the need to forbid you your little hobby. She can have her say about when and how you do it but she can't dictate alone what you can do or not. That is not a the way a relationship should go. You both love each others, don't you? Two loving people wanting to hurt each others isn't a sight anyone wants to see.
