It sounds as if your H is still stuck in replay as he has an OW. He will make no decissions whilst she is in the background. Have you read the stages of MLC. He has a long way to go yet.
A the moment he has it both ways. Two women who are stroking his ego and giving him love. He is ping ponging about at the moment. There is nothing you can do to help him he has to work it out for himself. You are right some ment do have problems deciding and wait for one of the women to make a move i.e divorce or bring the affair to a close.But you can work on yourself by detaching and giving him space and time. It is possible to keep the door open during this time.
Jack is right. Read the resources and make sure your H sounds as if he is in MLC. Only you will know. The resources are great for getting info and and advice for your situation.