This sounds awfully familiar. The thing is you have to think about your own kids. Not long ago I let down my guard - its easy to think of the life you've known with your parents as normal even when you know its not - and the next thing I knew my mother calls me when I'm 1600 miles away to tell me she's left my kids to their own and shockingly my father, whom I thought I could trust, just walked out with her.
Next thing I'm calling neighbors to make sure my kids are taken care of while I'm on a plane trying to get back as soon as I can. Suddenly I've messed up and its just like 40 years ago, all my fault never hers and the worst part is she blamed my kids!
One day you just realize you have to cut your loses and be a better parent than the one you had even if that means more disapproval.