Some of his behavior (the "I don't want to be an adult" comments, juvenile behavior, the affairs, etc.) could be signs that he is in an MLC. With the long-standing traffic with prostitutes, though, I'm not sure this is the case...
There are very good posters that can point you in the right direction to finding out if it is an MLC, and how to learn to cope with it. The bad news is: if it's an MLC then there is little you can do for them except give them time and space to figure things out.
Your H may still act out, be a selfish jerk, and even decide to leave you. (The fact that he hasn't apparently put any effort into leaving means he's still not certain that's what he wants.) Until -- or unless! -- he gets his own head together you may have little choice other than to ride out the storm, or walk away yourself.
Some questions and suggestions:
* If you have been having sex with him while he's been having affairs and seeing prostitutes, then absolutely get yourself tested for STDs on a regular basis. * Much of what he says is going to be "gaslighting" (rewriting history to fit his state of mind and mess with yours) but there does appear to a pattern of controlling behavior. Why is there a porn blocker on his computer but not yours? While you are working on your 180s, you might talk to a counselor about codependant behaviors.
Other books to look at:
"The Five Love Languages" by Dr. Gary Chapman (Sample chapter) "His Needs Her Needs" by Willard F. Harley, Jr. (Chapter one) "Getting Back Together" by Bettie Youngs and Masa Goetz (Limited online preview)
Me: 44, Wife: 39 M: 17 years T: 20 years Bomb on 08/25/09 1/13/10: MC started 1/28/10, 2/8/10: More bombs 8/28/10: Wife moved out No talk of D, no movement