I have to admit here that my lover/Master is not my husband, and it did START behind his back. But as soon as I got back in state, at home, I talked with husband and got consent. He isn't thrilled, but saw that being with Dog was helping me out of the depression that has been really pulling me down the past several years, so he agreed. If he hadn't, Dog and I probably would not have had anything beyond the few weeks I was out of state helping my heart-sister. It does kind of parallel our problem, but I am on the other side of it. Of course, there is a lot more to my story-isn't there always, but I don't really need to put it all up here-let's just say that hubby and I were having troubles before Dog and I got started, which may have been one of the reasons we did.
I wish I could help more. The only thing I can think of to suggest is to try and get her onto the forums. Maybe if she reads your posts, and sees that you really don't think she is weird, or that her desires are weird, she might be more open to trying BDSM with you. But maybe not. My hubby actually had more BDSM experience than I did, but I just can't find my sub for him. I don't know why I can, and want to, submit to Dog so completely, but can't let go that way with hubby. If I figure it out, I will let you know, in case it helps you with your situation.
Good luck to you.