I have been effectively asking that question for several years. No one ever gives a real answer that works. You can do all kinds of things to GAL, and yet you will still be unhappy, because your overall need of having a lover is completely UNFILLED. When a guy gets married, he effectively puts ALL of his eggs in one basket, his strongest most important needs are all PHYSICAL in nature, and he has committted himself to one and ONLY one person to meet ALL of those needs. Women on the other hand have needs that are usually NOT physical in nature and thus ANYONE in their lives can provide this. This is NOT true for men, unless we cheat.
I am still trying to get the David Deida books, but from what I understand of the passages I have read, men need to focus on becoming men again. Focus on male aspects and stop trying to please a women. In theory, your women will then desire you more. But he also seems to indicate that is they don't, then you as the strong alpha male must realise this and MOVE ON, their are better fish to catch in the ocean. In other words, stop trying to please her. Make yourself a strong confident man with MALE goals and if she does not work out for you, have no fear of DUMPING her. Not exactly a christian perspective on things.
Let us know how your discussion goes with the MC, I would really like to see their perspective on this subject.