He's just trying to get you to "change back".  Just let him know warmly that you are still invested in your relationship, just need some changes to happen in how you relate to his kids.

I think disengaging works best when you aren't too overt about it. You just step back but don't tell them what you're doing. If you tell them you're disengaging you get that reaction from your husband. 

Disengaging openly works best when the stepkids are being horrible and disrespecting you then you can clearly say you are not doing anything for people who treat you that way.

He wants you to do all the work for SD so he doesn't have to parent .  When problems happen, he an blame you. Not himself.  If you disengage he has to work harder.  You must be respected by DH and SD 

He wants his cake and to eat it too.

If he drops the D card again, tell him to pack his shit, collect his failed family breeding experiments and not to let the door hit him in the ass on his way out.

Btw, disengagement isn't failing for you, it is succeeding brilliantly.

My DH told me last night that I was "free to go." He doesn't want to see me in pain but he doesn't have a choice. We have sole custody. I begged him to just run away with me. No one has ever picked me. I have always been the one left behind. I know it's a lot ot ask but I just wish we could go away and be happy. So, I either have to suffer and smile or leave and be miserable. No win scenario. It SUCKS. 

But, I am not "going back to normal." I cannot for my own safety. Girl, believe me. Somethings gotta give. And it don't have to be you!

I don't think it really matters what you do, you are going to end up the bad guy if that's how the dynamics are set up.  Looking back, I wish now they could say that about me....that I did nothing.  I would rather that than have given my whole heart and made myself so vulnerable to people who just broke my heart.  I gave all I had and I was tossed aside just the same.  Hindsight is 20/20 but I would rather have kept all my love, time, energy and money than have wasted it on my skids who couldn't care less if I live or die.  I'm like wallpaper.  If you notice me, you might like it but you're probably not gonna notice it.  Two years of trying to accept this and pick up the pieces and it still hurts and angers me.

hes only trying to get you to submit again and things will go back to normal,, which is great for him but shit for you.  You being disengaged means he HAS to do everything .   If he says dont mention her name etc etc ,,, dont 

Disengagement isn't meant to save marriages. It's meant to save the people who use it. Saving the person who disenages may mean a marriage ends because the marriage perpetuated the problem that pushed the person to disengage in the first place.

So I'll say I've always thought disengagement is best for those stepparents who are obviously being used and not respected; who rarely comes into contact with skid(s) so their "help" is unnecessary but also unwanted or causes more drama than it's worth. (Like if you're with a man with older children planning a wedding with a high conflict BM--you don't need to go if you don't want to, feel comfortable. Disengage from the whole process). I've always said disengaging when you are a primary parent like myself wouldn't work unless your spouse that can coparent with the BM or do it himself.