The MLCer exhibits teenager qualities during the crisis. It's when they go back to where they were stunted emotionally in life, usually childhood, i.e., early teens. They have to go back and face the demons that stunted their emotional growth and then grow up from there.
Worrying about whether the affairs will end or not is a waste of time. I know, you want your h back, but right now, the man you love is gone. In his place is this spoiled rotten kid who most likely threw spit balls at the girls or got under his mother's skin about things he shouldn't have done.
The affair has to die a natural death and one that you do not have a hand in. It could take a while, but it will die at some point.
You might want to pull up the MLC Archives and read some of the threads over there. I initiated a thread that may be of interest to you in the Archives. The thread is located on page 206 and it is entitled "Stages of MLC Through The Eyes of a Visitor". This thread was initiated in October 2002 and it might help you to better understand where they are at mentally/emotionally.