Talk to her without fighting maybe? In my opinion (which is sometimes way the fuck off), you pushed so hard for her to wear the sexy lingerie, and even though she really disliked doing that, she wore it just to please you. Even though you *thought* it would be a major turn on, subconsciously (fuck you Sigman Freud) you knew she didn't enjoy it, and was just trying to make you happy.
Understand I'm in no way trying to call you a bad person for pushing for that, I mean any man cannot say he wouldn't like to see the girl he loves dress up in something totally sexy! (except me, I'd rather just strip her down and cuddle, call me gay if you like, others have~)
I dunno, talk to her about it.. and even though it may be hard for you to say it, tell her that if she doesn't like wearing the lingerie and was only doing it to make you a happy little boy, that you won't push for her to do it again. After all, doing erotic type things are only fun if both parties/people get that great feeling of happiness and pleasure, for me anyhow.
In six years have you never found a major fault in her that bothered you, besides this? And, do you ever think about the two of you spending the rest of your lives together? Psychologists and other shrink type people say that as you start to realize the idea that marriage might exist between you two, you start to find faults in the other person, and the rest is if you can work through those and be happy. If not, then it might be time to reconsider.
I don't really know what you're looking to find. Advice on how to work this out? Or just a solid: yes you should get rid of her - or no you need to work this out because it's not really that big of a deal.
No clue if any of this helps, it's late and for some reason I felt like analyzing things way too much, sorry
