How well did you know him before you married him seven yrs ago? Anything in his past that could be triggered by some recent event and throw him into a crisis?
Has there been any issues with inappropriate behavior since you'be been together? How does he act around women? Does he get flirty? Does he make sexual comments to you about other women? Does he have private friendships with females that just happen to exclude spouses? If you answer yes to any of these questions, you will need to seriously search your heart and know if you really want to continue with this man. If there has been a pattern of pushing the marital boundaries, then I doubt the problem is MLC, but rather, waywardness.
Sometimes MLC continues for a looooong time. Are you prepared, emotionally---financially---spiritually---(well, let's just say in every way) to take on the challenge? This is not going to be resolved overnight, if he is having a MLC. IMHO, if a man is ready to sexually share his W with another man, in order to experience his own sexual needs from other women, instead of being faithful.........the fat lady is warming her vocal cords on this MR. KWIM?
If you decide you want to fight for your M, then the first thing you need to know is that fighting for your M means you don't fight with him. Seriously, you have got to throw out the old score board. Don't misunderstand, I'm not telling you to become a doormat. I'm saying that you will need to change your mental attitude and learn a new method that does not include screaming, shouting, cussing, slamming, throwing, cold shoulders, icy tones, one-ups, getting even, and........the rest of a long list you may be guilty of using, IDK.
He is not going to change any time soon, if ever. So, how do you respond and/or react to this guy he has become? We can't tell you everything in one post, but we can help you get started. The post that was sent your way by Cadet or Job, has a ton of valuable information, so please don't ignore it. If you need a guide as to how to behave on a daily basis, look to Sandi's Rules. The next thing I suggest you study is the subject of personal boundaries. The purpose of boundaries is all about protecting your feelings, dignity, and respect. It's not about controlling the other person. The only one you have power to control is yourself. Boundaries are necessary, but they are not effective if there are no consequences for the person who ignores your boundaries. Make sense? We can discuss this subject more, if you want. Just a suggestion, you may want to research boundaries in a relationship.
If you have a set of moral standards, spiritual beliefs, etc., that guides your daily life and how you interact with strangers, co-workers, friends, and loved ones........then you use those guides to form emotional, protective, boundaries. Remember, it is not about punishment, control, getting even, or paying back. Study the link on boundaries.
The next important, and I think the most misunderstood technique, is DB detaching. The link in the homework is pretty wordy, and if I can remember, I'll send a copy of DB detaching that is a shorter form, to get you started. I think it is hard for the newcomer b/c they are usually the ones who want to save the MR, and their emotions have been traumatized. IMHO, it seems most LBS's have difficulty maintaining even keel. Most LBS's will dramatically shift too far up or down, east or west, left or right. It's like driving a vehicle on the street. You have to stay between the lines, or take a big chance of making things much, much worse.
Your H has made it pretty clear that he is not interested in you or the MR. The more you try to persuade him to see things differently, or the more you try to vocally convince him the M can change for the better..........the more he is going to resist, He is in an emotional battle with life. He will drag down and/or fight anyone who tries to tell him what he doesn't want to hear. He cannot learn through hearing words. He has to learn visually and experiential. Anything else is useless. This is one reason facing the consequences from dishonoring boundaries works well. Boundaries are not an opportunity to lecture. He is tone deaf. He can't read anything you might suggest, nor watch a video or listen to a tape about marriage. Those features have died. Therefore, you have to discipline yourself when you have the desire to explode on him, or try once more to just have a relationship discussion. It only sets you back to square one.
I said all that ^^^^^ to introduce the action I believe works best. Based on the mindset he has, he sees you as another source of emotional pressure. Maybe he sees it as the main source of unhappiness, or whatever. He sees himself happier if only he were free. His life is passing by too quickly and he will resist anything that gets in his way of grabbing for the gusto that awaits him. Ugh! Unfortunately, that includes having other women. If he had high morals, they seem to be gone, and currently, he is suggesting an open M. That tells me he is willing to put not only his M, but his W at risk......by inviting others to be intimate. He is so wrapped up in himself that he doesn't see anything else. He may have an unmet emotional need, but he is currently unwilling to "do the right thing" like a logical, sane adult. To cut to the chase, I am suggesting you become the dump-er, instead of the dump-ee. Let your attitude, GAL, personal attention, one-on-one time, home environment, family activity, etc., paint a picture for him. He sees he is losing his W of seven yrs. He no longer gets text messages from her throughout the day/night, checking in with him. If he wants to spend the night out, he has to get a babysitter, b/c his W is out getting her own life. He doesn't know what she's doing, b/c she doesn't care to share anything. In fact, there are several things about his W that tells him she is moving on. She doesn't ask him anything about his life, their MR, his future plans........nothing. She doesn't complain, preach, get revenge, nor act like a victim. He doesn't know what is going on in her head, but she looks and acts differently. He wonders if she wants a divorce. He wonders if he has lost her.
I can almost read your mind. "Isn't this exactly what he wants?" I can explain more, later. Just let me assure you that I am not telling you to do any action that goes against your personal belief system. I'm not telling you to do anything with revenge or hatred. You need to let him go. I mean, you behave as if you have emotionally let go of him. That's what he needs to feel. No pressure from you. Another thing you have to do is let go of the anger. Okay, so that will be tough, but don't show anger to him. You can be spunky, but not angry.
Got to close this long post. Hope I have not thrown too much into one post. If you have questions, please ask.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!