Although many individuals abstain from sex for complex reasons such as religion or morality, for some individuals sexual abstinence is simply a lifestyle choice. Those individuals who fall into this category may have a dislike of sex, or are simply not interested in it. They may view sex as an unnecessary part of human life. As with other lifestyle choices, this attitude toward sex and relationships can vary greatly. Some who choose such a lifestyle still accept sex for reproduction, some engage in romantic relationships, and some engage in masturbation.