I think that by him throwing caution to the wind with regards to not being sure if he will change, magnifies how little he can empathise / relate / understand the magnitude that his actions have had on you.

I think men have primal urges and he actively sought out to relieve his urge. My definition of cheating is doing something that you wouldn't do if your partner was right there standing over your shoulder.

To me I think of it like this. What do you think his intentions were by doing this? I kind of believe that he had no intention of meeting up with her, hence it was online as this provides a "barrier". There are levels of cheating, and then there are levels of cheating.

If he can show remorse and some kind of inclination to change his ways, then perhaps there may be a chance to move forwards.

However, his stand off attitude at the moment, suggests that you need space to come to terms with what he has done.