I feel so much what you're dealing with. My own MIL has been both an overt and covert enemy of my M, continues to bless and encourage her daughter's adulterous relationship with the OM, even after all the kindness I've shown her over the years. If you remember, the MIL is also a selfish, three-time WAW and adulterer, and she has this twisted belief that D is usually the best solution for even the least disagreement. I've pitied her before the bomb, but I can't help but despise her now.
MIL's own parents were bitterly divorced. Thus there's a long ugly trail of D in W's maternal family.
But then I guess you really can't expect too much from them thar yankees (sorry, Theo, I had to say it. )
Seriously, though, Yoyo, your H sounds like he's doing what my W has done, which is to embrace immoral, selfish enablers, family members whose own behaviors had repulsed our spouses at one time, but which they now excuse. My W once asked me (practically begged me) to save her from ever turning out like her mother.
In the end W chose to become just like her mother. This is her choice. And now I must let her suffer the consequences of that choice.
) 
