I went for "other" because of the verb "deny". That implies it's a commodity to be traded for a price. Sex is supposed to be a consensual gig. If it's done as a favor, such as "I'll mow your lawn while you're on vacation", then it has no meaning.
what if you grow "disinterested" in sex, and no amount of counseling has helped?
If no 'counseling' helps- what about medical advice?
For instance there are medications that affect libido- anti-depressants are a common cause for loss of libido- and one I have heard can be a huge issue- I know of women who have had their depression 'cured' by antidepressants, but completely lost desire for sex as a result- which caused real issues within their marriages.
Ultimately I think that a huge imbalance could lead to harm or even an end to a marriage. It depends on everything else in the relationship and how important sex is to the partner who does want it.