HP & Mrs. NOP- I hear ya! What y'all are saying is possible-- that if ZB stops letting her off the hook, she may have to face her own sexual possibilities. I certainly agree that acting like everything is okay when it isn't is the first layer of concrete in that wall that separates you from your spouse.
However, what I'm saying is also possible... namely, that Mrs. ZB made this decision about who she is decades ago, is firmly entrenched in this kind of thinking about herself, and, as ZB pointed out (at least I think it was ZB) she knows he will not cheat and he is not going anywhere. What will be the consequences to her if she continues to refuse his invitation to grow?