I agree that your H feels justified in what he is doing because he already asked for a divorce and moved out.
You're right, this is not the man you married. His brain is addled right now with all the hormones rushing through. It creates the fog and makes good decision and judgment making ability very hard.
An affair built on lies and deception very rarely work out long term and usually burn themselves out within 6 months to 2 years.
It does all come down to what you decide to do about your marriage. I agree that full all out exposure in this case would not be the way to go because you have to work there too. I know it's in your face everyday but exposure would make it more so. You've said that this is a crucial time in your career also and a much as possible peaceful work environment is more to your advantage.
It sounds like you have your H intrigued by your 180's and changes. The ow has been down this path before. If you so decide you have no problem being the better option for your H.
I think you are extremely wise in giving yourself time to figure out what YOU want. If you want your H and a new M there is a chance that that can be rebuilt. If you decide that you want to walk away and not look back, you have that option as well.
You are in a unique position with a strength you rarely see this early in a sitch. You have a lot of options in figuring out how you want to handle this.
