1) carry on with our fetish, but hide it from our partner
2) take the risk of blowing the relationship and tell her frankly
For me personally, I took the second route and it turned out much better than I expected. My girlfriend is very cool about it, seeing it as just a little kink that I have. She is even touched that I trust her enough to tell her something that no one else knows about. I'm really lucky that my girlfriend is very open-minded and tolerant about my kink.
My question to anyone who has told his girlfriend or who plans to tell is: how did/will you do it?
I'll get the ball rolling with my experience.
I have always known that my girlfriend is open-minded. She is well-traveled and have met many people with slightly weird interests. As part of my preparation, I once asked her about her views on homosexuality. She said that she is totally cool with it. In fact, one of her good friends is openly gay and she doesn't feel anything wrong with it. That gave me some confidence, but of course accepting a boyfriend with a fetish is a very different story than having a homosexual friend.
As for the actual action of telling her, I chose a moment right after we had lunch, so that neither of us was busy with anything and we were both relaxed. I then started with the comment that "There is a little secret I would like to share with you." After which, I proceeded to tell her that I have a deep fascination with long satin dresses and that I would sometimes put on one of these dresses to enjoy the feeling of the soft fabric. I tried to make it short, so as not to overwhelm her with information, but emphasized a few points:
1) I'm not gay. I love her and have all the normal sexual urges
2) I'm not a full-blown cross-dresser. My fetish is limited to long satin dresses and don't fancy putting on bras or heels. Neither do I have the urge to wear a dress in the public
3) I've had this fetish since I was very young and it's certainly not her fault
Judging by the result, my approach seems to have worked.
There you go, that's my story. How did you tell your girlfriend/wife?