I agree. I am not sure what you are speaking of, not that you need to share i you don't feel comfortable doing so, but there are some things I would not tolerate.
If I made something clear before marriage that it was a dealbreaker, and he subsequently "went underground" with it to "get me" while keeping it, that is deception, and I would seriously consider a seperation until such a time the deception was stopped. I could not trust someone like that, and trust should be a fundamental item in a marriage.
If it were a sin, I would outright refuse to allow it in my house. If it were just an irritation, we would have to come to some sort of agreement. However, being that there was decption from the beginning, that, in and of itself, is a sin.
I would seek godly counsel with someone that I trusted, someone that would seriously look at the issue, not point fingers, and offer solutions and assistance in reaching those solutions. If he refused to work on a change, seperation would be a very serious consideration for me. (I do not advocate divorce, but a serious seperation can bring about a good reconciliation when used properly.)
I hope you find a solution.
Now, your problem may not be as serious as I am thinking, so my answer may not be what you are looking for. So, this is all just MO.
If I made something clear before marriage that it was a dealbreaker, and he subsequently "went underground" with it to "get me" while keeping it, that is deception, and I would seriously consider a seperation until such a time the deception was stopped. I could not trust someone like that, and trust should be a fundamental item in a marriage.
If it were a sin, I would outright refuse to allow it in my house. If it were just an irritation, we would have to come to some sort of agreement. However, being that there was decption from the beginning, that, in and of itself, is a sin.
I would seek godly counsel with someone that I trusted, someone that would seriously look at the issue, not point fingers, and offer solutions and assistance in reaching those solutions. If he refused to work on a change, seperation would be a very serious consideration for me. (I do not advocate divorce, but a serious seperation can bring about a good reconciliation when used properly.)
I hope you find a solution.
Now, your problem may not be as serious as I am thinking, so my answer may not be what you are looking for. So, this is all just MO.
The fact that I'm still married today is proof that seperations can work when done the proper way - and with lots and lots and lots of prayer. If your husband is sinning, you need to respectfully hold him accountable for it - or find trusted members of your support system to be accountability partners who can talk w/ him about what he is doing. You also need support for yourself and not blame as the op's have suggested. The reality is that if it's something that you specifically asked him not to do before you were married, he knows that what he is doing is at the very least wrong in the confines of your marriage. Otherwise, why would he bother hiding it? My experience is that when someone is doing something they know they should not, there can be alot of shame and anger associated with the act. How we wives react to our husbands' wrong doing can have far reaching affects on the situation.
But again I can not stress enough the power of prayer and finding the right support system/friend for yourself as you go through the emotions and deal with this as a couple and as a wife.
Well, I went one direction after we left, and they went the polar opposite. They went completely hog wild after leaving and couldn't understand how I ended up a social and religious conservative. I'm really sad about that, but I can understand it in a way. I know looking at me in my headcovering and long skirts with a bunch of babies brings up very painful memories for them, related to the cult.
For me, I've always been very conservative, politically, modesty, etc. So I suppose everyone expects it from me, even though growing up, I tended to have very liberal friends. But most of those are still back home - so we only keep up on facebook. It's been a great lesson in tolerance and loving people for themselves even when I think their views are completely nuts. They probably feel the same way about me.
.
I've been lazy and selfish. I haven't been spending time with God like I should. It's like I'm stuck in this rut! I want to be an encouragement to him and be the wife that God is calling me to be!! But it's so easy to go back to my old ways. 
Prayer was the key for me going through the tough times.
Follow Mothering