I can relate somewhat to what you are saying. My ex does not seem as interested in his children as much as before. He is doing a lot with OW alone rather that with the kids. I actually perfer it this way since OW is as bad as he is.
He made a weird comment the other day about my son. He said that after he goes to college he plans to not be a big part of his life anymore. I thought how weird is that.
Since most of what he says is just gibberish, I ignored it.
I myself have not heard from ex in 10 days.
So, I agree with Snodderly, I think our ML'ers are hitting the withdrawal part of this process.
Me: 46 H:44 Together: 25 years Married: 20 years Separated: 11-30-06 Divorced 12-21-07 OW: EA began 2005 PA began end of 2006 3 children,20, 16, 6 ex asked for forgiveness 01/16/11