I don't want this to sound like plain old "piling it on", but you should also consider the 'learning all you can' exercise for another reason.
Giving this a little more time to play itself out can be better for the kids in another way. Discuss it with your L if you want more opinions of course.
If he is considered sick by this new T, and it sounds like he may be prone to living in the gutter with these volunteer victims of his abuse ... he is not a person you want your kids to be exposed to. Not him, or his partners in this lifestyle. You may need to extract enough clinical information and professional input from this T to arm your L. Keep your journal of these conversations he has with you, and his changing stories, his expanded revelations of unacceptable behavior, etc.
I do feel sorry for him as he sounds lost and unable to control himself in this at the moment, just as he is unable to erase the past or control you in the D. But his problems are not automatically yours to share. He must become responsible for his actions and mental health. He may be trying. But will he succeed? Why did it take you filing the D?
You should be prepared to not just complete that process if it is what you choose, but unfortunately for him, you should be prepared to keep him from exposing the kids to these kind of people. If you can prove they are not just good honest women he fell in love with; but a part of an unhealthy behavioral addiction ... you should have an increased control in any kind of visitation he might hope for.
Again, talk to your L. See if there are other valid reasons to give this some time and see where it goes.
