Question: Men are not entitled to sex. So what is a man to do when he is in a committed relationship when his woman is unwilling?

Sex is a valid WANT/desire not a need, and I think this train of thought extends to sexual fidelity aka monogamy. Monogamy is a valid WANT/desire not need.

Answer: If a man's wants are not being met, then he has no obligation to meet his partner's wqnts. A man should put the fidelity on pause until steps are taken to address the problem and sex resumes.