I agree with everyone who suggests not believing your husband on this one. I'm sure if you argue with him or call him out it will be a huge argument and twistation of words, but yes, most As lie all the time. It's a part of our nature. I manipulate more often than directly lie, and have cut that down to a minimum, but I'm good at it when I do. My RABF told me the other day straight out that he has probably lied to me a thousand times in the year we have been together. I can't honestly imagine someone sitting there with a prostitute in Vegas chatting it up for $150. The fact that he brought it up indicates a huge amount of guilt being experienced. I know my ex waited a few months until we were in a fight about something else to confess that he had cheated on me (with a close friend of mine). As time elapsed, more details seemed to magically come out of the woodwork. The story I first got as a result of his guilt was nothing close to the full picture of what actually had occurred. Good luck, be wary, and I'd take the advice of the others and go to some Al-Anon meetings to get a program for YOU. The most important thing you can take away from this site right now is focus on yourself.
The 3 C's:
You can't Control this.
You didn't Cause this.
You can't Cure this.