I must admit, I only got about halfway thru your long post, but I think I pretty much got the gist of it:
Your husband is a serial adulterer, and refuses to end this behavior and be fully transparent with you (at least without you hounding him about it).
The question is, what are you going to do about it? What are you WILLING to do about it? You do realize that his current attitude about it all is because he's pretty much been able to return to the marriage each time in the past, without any real consequences from you, don't you? I mean, you'd cry or get angry or beg or plead, but I'm not seeing where there's ever been any real meaningful consequences for his destructive behavior. Because of that -- and because he's probably a narcissist personality to begin with -- he's developed a VERY strong sense of entitlement and even INVINCIBILITY, and I highly doubt he even thinks he's in danger of losing anything meaningful to him at this point.
What ARE your true, core dealbreakers? -- your "N.U.T.S." as it were? I like to call them "My Boundaries of Personal Integrity," and with most married people, one of them is "I will not live in an open marriage," or "I refuse to share my husband" or "I refuse to make a priority someone who treats me like a convenience," etc.
Without these, you will find yourself adrift, like the proverbial "frog in the pot of boiling water" story, and then suddenly you wake up, look back at your life, and say to yourself "What was I THINKING???"
Put another way, would you have even CONSIDERED marrying a man like this, if you knew he was capable of this? Now that you ARE married to him, why should you tolerate it now?
