Then this is what I thought to begin with. I am sorry about the death of you MIL --but for your FIL to "move in" with someone from church three months after her death --is something out of a crazy novel. Like one of the other posters commented --this is NOTHING but superficiality and in my opinion "values" other than Christianity. It is very, very sad.
It gives a clearer picture as to why your H is in MLC. A lot of family dysfunction going on here. And now your H is going down another "dead end street"!
So very sorry about all of this but still nothing that God can't deal with--