Hello and thanks for writing to us. My name is***** am sorry to hear you description of what is happening with your husband. While it must feel good to see him sober, I imagine seeing him go through a phase of this emotional "awakening" is scary, frustrating, disappointing and also confusing. He has also breached your trust and sober or not, this will need some repairing and commitment.
While peer support is a huge part of the NA program, I am with you that something seems off here. Sober or not, there is no justification for flirting outwardly with other women nor allowing yourself to get swept up in new emotions of desire and lust when you are married since turning sober. To me, I can understand that for the first time in a while, your husband's drug use is not interfering with his ability to think and feel, however this is absolutely not justification for infidelity on any level.
So I would trust your gut here and enter into counseling with him before this gets too late and he allows something to happen that will put a serious damper on your marriage. If he loves you, he will agree to this as he is now admittedly a different person, and the two of you need to "get to know each other" again and also redevelop your marriage without substances as a factor. It is a great sign that he is reinforcing he loves you and wants to stay married, but he needs to back that up now that he has shaken your trust.
I hope this helps confirm what you are feeling although I know it isn't easy to face this. I am here to talk more if you'd like.