My husband is soliciting tranual men, aka chicks with *****, on craigslist, what should I do?

I already confronted him about this with a very long letter several months ago after I caught him watching chicks with ***** and soliciting men with **** on craigslist.I was very open with him and told him that I didn't think that it meant that he was gay and I was open to him exploring his fantasies but that I just wanted him to be safe (ie use a condom) and that I wanted him to stop doing all of this behind my back because it makes me feel cheated on. I think that this is of utmost importance because if he is doing this behind my back and gets a disease (such as Hep B or HIV) I could p it along to our 4 month old daughter because I am still feeding. When I confronted him before he focused on explaining the but basically ignored the craigslist solicitation. I don't know what to do at this point. I am torn between confronting him again, which would cause me to expose the way that I have been able to find out about this solicitation and would keep me from finding out if he actually meets up with someone, and just doing watchful waiting in order to protect myself. I am wondering what to do and also what is the deal with this fantasy? Does he just want more ? And most importantly what is the best course of action in terms of confronting him/not confronting him in order to protect myself? (other than just wearing a condom)