The fact that your wife thinks it's okay to discuss her boyfriend with you, and their dates, speaks volumes about your stance throughout this long ordeal, Ox. Now that you are at this stage I guess you're going to play out the hand your counselor is advising you to play, but this is all just SO wrong, on SO many levels.
I get into some pretty spirited debates sometimes on this forum with people who contend that the best time to lay and enforce boundaries is LATER, after you've made your improvements and after the poster is "better prepared" to deal with them. I always STRONGLY disagree, saying that if you don't lay them early, then their wayward spouse's actions will become acceptable and tacitly agreed to. Crap behavior is crap behavior, and should ALWAYS be addressed early on.