I think you're very, very gracious for having put up with this treatment for as long as you have. You're in a relationship with him, not her. You don't need to negotiate anything with her, if you don't want to. It's polite, but not necessary. I think you need to start having a relationship with (only) him and let the two of them work out their issues, if they can. If he can't have a relationship with you and treat you in ways you want to be treated, then is it a relationship worth having, anyway? There should be a middle ground between being courteous to your partners' other partners and giving in to their every demand.
(My GF saw the look on my face while I was writing this and got very concerned I was angry about something... I had to explain I was upset about this post and the whys of it. Her words were, "I would never put up with that." We've never known anyone to have such restrictive and comprehensive rules. YMMV.)