How are you able to believe your W about anything? (my H has a history of lying to me right from the beginning of our M).
Well, that's a different story. What has he lied about?
I guess I was just talking about the semi-normal sitch around here where an otherwise faithful, honest spouse is caught or admits to cheating. If your H has a history then it complicates things a bit but still doesn't change the fact that a lot of what DB is about is focusing on you and not H or his A.
Maybe you can elaborate on his history and it would help us get a feel for the entire sitch.