Jayla...
As a FWH who is also in Plan A trying to get back my BS/WW, I can and have seen both sides, even though I'm only a few months from my own D-Day.
As a FWH who also had a fairly casual A like your WH (and multiple ONS's)...I agree...it's a bit too early.
During the first month after my D-Day, I didn't change my behavior that much - I was still in contact with my OW, lying to my BS about the details, I toyed with thoughts that maybe I was better off single and dating, I hurled alot of LB'ing anger at my BS/WW for her own A and used it as justification to stay in my former foggy state...
But the pain of losing my lovely W was just too much and cut through all the B.S. I was trying to make myself believe (and I mean bulls***, not "betrayed spouse!" <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" /> )
Once I started Plan A and committed to making my M work (just 1 month ago), my W said "why the sudden change, just 2 weeks ago you were with her again?"
And all I can say is...I was seriously foggy...but it didn't take long to realize I wanted my M to work. I think serious fog is normal immediately after D-Day, it's hard to break old habits and even to admit to oneself that a mistake was made and you better own up to it.
Your WH is going to have to do a few things right now...he's already admitted fault and regret, but he also needs to do the following (and I know, because I did them):
1. Be totally honest with you about everything, every detail, and about the pain it has caused you
2. Stop making rationalizations for his behavior ("It meant nothing" "It was just sex") - those are excuses and he's trying to absolve himself of responsibility by saying them.
3. Prove to you that he can be trustworthy again by owning up to his sins and making drastic steps to correct them (meaning, he can't walk around like nothing happened - he needs to acknowledge your pain in a loving way every single day).
I would recommend this book to HIM - DON'T READ IT YOURSELF, this book is ONLY for the WS - buy it for him as a gift, leave it on a table for him...
http://www.aftertheaffair.net/Maybe it will help him realize the damage his current behavior is doing. It did for me. It's too early for me to tell if my efforts will bear fruit, as I'm only 1 month into Plan A with my own WW, but from the perspective of the WH I have already seen results.