Humans are sexual beings. Our sexual nature is the cornerstone of who we are. Some like sex more than others. Some people have stronger sex drives than their partners. Often the issue with a couple is that women need to have intimacy to have sex and men need sex to be intimate with their partner.
Not wanting sex might have nothing to do with sex but more to do with what is happening in your relationship. If you have been critical, abusive, unloving or emotionally unavailable, perhaps these reasons are keeping sex at bay. Communication is an important part of a healthy, loving relationship. If you aren't communicating verbally, you won't be communicating sexually either.
When The Idea Of Sex Doesn't Turn You On