Telling my fiance (and my brother) has been one of the best decisions of my life. After telling them, and their respective reactions were both better than I dared hope, I felt a weight lifted from me. My fiance and I are now closer than we have been in all the time that we have known each other, and without getting psyched up to tell her by you guys, and by my brother, I may have taken it to my grave.
To anyone who has this particular dirty little secret that they are keeping from a significant other, if you are serious about them, TELL THEM. I assure you, my first statement in this post is 100% true.