Asexual
From wipipedia.org

An asexual person has little or no interest in sexual activity. They are likely to be celibate unless they have become asexual during a relationship, in which circumstance they may engage in sex without much satisfaction.
An asexual person is content without sex. This is distinct from an enforced, chosen or circumstantial life without sex where the person would otherwise be more content (and possibly stable) if they engaged in sex.