So you are moving out, and she doesn't work and is home with 3 small kids?
Even if you talked to a lawyer about this I would strongly, strongly, strongly advise you to go ahead and file for legal separation or divorce with custody and support agreements in place BEFORE you move out.
The issue is that right now you actually have some power because she is desperate to get away from you and will give up long-term outcomes for this short-term goal. BUt as soon as you move out you are trapped and she is sitting pretty. She will have every motivation to keep this the status quo forever, so you can expect that she will never get a job, she will block any attempt to sell the house, eventually OM will move into your house and you will be paying her and OM through the nose forever, even indirectly as you will end up paying for all your kids college tuition while they are traveling the world. I have seen a ton, ton of guys come through years after their separation/soft divorce trying to extricate themselves from this type of situation and there is usually nothing they can do because they agreed to this years earlier in misguided attempts to placate their WW or WAW hoping to nice them back.
You need to accept that you cannot control whether you get divorced or reconcile. But I can tell you that either way, you can and will be happy again unless you allow yourself to be trapped into a bad situation with custody and finances.
So, my firm advise is to put yourself in the strongest possible position for either outcome. Get a legal 50-50 custody and financial agreement in place before you leave, and make that a condition on leaving. Impute full time income for her (if you are gone, she is working!), standard child support, limit any alimony to a couple of years, future costs like sports, cars, college are specified as 50-50. I would also strongly, strongly suggest you sell a house immediately even if you take a hit in doing so. Again, far cheaper in the long run to take a hit now than to pay indefinitely and then take a hit later.
Depending on your locality, this legal protection is going to be either strong legal separation or filing divorce. That is really just semantics. I will honestly say that filing divorce does not really make it any less likely that you would reconcile, but it does reduce the chances of getting stuck in limbo purgatory.
If you do this, you will be able to move on and I would say there is a 90% chance that in less than a year you will look back at your posts and not recognize this beaten down guy who put up with this treatment.
And, even if this sounds terrible to you now and you can only think of reconciling, what do you think is more likely to happen? She decides she doesn't like taking all of your money, and using you as a convenient babysitter for her new, fully financed single lifestyle? Or, she has to support herself and learns the hard way that single motherhood isn't really all that great.
