I learned from a lesson from my ex... careful what you look for because you just might find it.
I always thought something was up and finally one day he left his email up and yep I found it.
Anyway, I don't know what's what and I'm sorry. I do agree with LunasMomma, if you offer an ultimatum then follow through with it. I'm not sure I buy the strip club excuse or not. To me it's not worth lying about, but again, I'm not sure what your reaction would have been if he just came out to begin with about going there.
Sorry, hang in there. I would suggest though that if you are always going to have it in the back of your mind that something is up, then move on. It's not worth going day to day always questioning his every move and action.