As far as your question goes that is much tougher. Your WH is very confused. Normally I would say detach/NC. This is harder because of your business. I am not sure how your business is going to survive this. I am assuming your WH is an integral part of this business. Can he be replaced in the business?
The confusion certainly indicates that he is MLC. The NC is to protect you and I am not sure of your feelings about all of this? You seem to treat him and his affair as OK?
I think your boundary is good however you can not enable him to have you, the OW and the business. He is going to get rid of one of those things. It should not be you.
I think the most important thing for you to do is to start living your life as if he is not coming back because I think his replay has started down that road. GAL. Work on being the best MOM you can be.