You have to look at it clinically -- loss of desire is often a clinical problem. If you look at it as love=sex, then you will feel resentment of course.
I think that's a rationalization -- unless there is a medical reason that precludes the physical ability to have sex, then not having it is a choice and a decision. Even without desire, you can still have sex for the benefit of your spouse. According to MWD, for women desire often follows action, so after you start you find you enjoy it. I believe she uses the analogy of jumping into a slightly cold pool -- you're not interested in taking the leap but once you're in and acclimated it feels good.
Part of the traditional "marriage contract" is that you will be faithful to your spouse, that you will not have sex with other people. Therefore, your only allowable source of sexual gratification is your spouse. If you are meeting their needs and they are comfortable in your relationship, but choose to deny you sex, that seems cruel and unreasonable, and cannot be excused by clinical lack of desire.
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015
