I never said it was her fault, but it does leave him vulnerable to a woman who would love him and is not his wife. About 20% of marriages are functionally sexless. It is quite common for women to sleep with the Alpha males without a ring and then deny sex to beta husband they do marry.
As I said, the proper response to alack of affection is divorce, not infidelity.
But you say that not all men can “afford” divorce.
Sounds like more rationalization to me.
Your endless speculation about him not getting any at home just seems strange