The reality of the situation is that most couples don't do anything about it with each other because one spouse may be completely content and the other maybe unhappy. This happens more often than not in long term relationships where the sex drive, desire and frequency of sex is not what one person wants, but their partner seems to be fine with it and can happen with both men and women.
This usually is not a sudden realization but one that takes place over a period of time and then at one point or another just becomes unbearable for one spouse.
As a sex counselor and marriage counselor, I recommend that couples heading down that road of disaster to take the time and talk about it before it gets to the point where resentmeant and cheating takes over.
If that time has already come and gone and you are the spouse who is miserable, and unhappy then something needs to be done and that is to get help from a sex counselor or sex coach that understands human sexuality.
Sex coaching and counseling is much different then marriage counseling because it is solution based and deals directly with sexual issues, sexual health, techniques, fetish's, fantasy, sex drive, hormones and other issues. Sex counsling can be done as a couple or individual, but one thing is certain everyone deserves to have a healthy happy sex life!