"Numerous studies show that men and women enjoy sex most in a meaningful relationship, typically a long-term committed one. These studies indicate that pleasure can be more meaningful and enjoyable in long-term committed relationships. Those who abstain from all sexual activity have no intimacy and no pleasure. Those who masturbate alone derive pleasure without intimacy. Those who purchase prostitution services derive pleasure yet have very little intimacy. Those who have one-time sexual encounters in a “one-night stand” also derive pleasure with little intimacy over time. For married or cohabiting couples, sexual intercourse includes both pleasure and intimacy. In relationships, sexual intercourse has many functions, including reinforcing commitment and loyalty, providing affection, and offering pleasure and bonding. Some couples seeking parenthood have sex to pleasure themselves while getting pregnant, while others become distracted because sex becomes goal-oriented rather than simply expressive. For long-term relationships that have endured hardship, betrayals, offenses, anger, arguments, and ultimately forgiveness, sexual intercourse can take on a profoundness of its own and may enhance trust and closeness while sometimes providing sexual healing to wounded egos and feelings. Extramarital affairs are intimate relationships with a person other than one’s spouse that may be sexual or nonsexual. Most U.S. extramarital affairs are sexual and not consented to by one’s spouse. Scientific studies have found that men were more likely than women to have an extramarital affair and that most men and women do not ever have an affair. Marital infidelity has been and continues to be disapproved of by the general public. Affairs do not always lead to marital or relational dissolution, but in most cases it is better if the offending spouse or partner confesses the infidelity rather than simply gets caught. Sexual orientation is the sexual preference one has for a partner: male, female, both, or neither. Heterosexuality is sexual attraction between a male and a female. Homosexuality is sexual attraction between a male and another male or a female and another female. Bisexuality is sexual attraction to both male and female sexual partners. Sexual orientation, sexual desire, and sexual behaviors are different dimensions of sexuality. Sexual desire consists of attractions to sexual partners that exist independently of behavior, while sexual behaviors are actual sexual actions and interactions. Orientations, desires, and behaviors are not always the same thing, although they sometimes overlap. A heterosexual male may have had a homosexual experience in the past, or may at times desire males and females regardless of his actual sexual activities. A lesbian female may have had a short-term heterosexual relationship yet define herself as a lesbian. Edward O. Laumann and other researchers surveyed about 3,400 respondents in the largest sociological study of U.S. sexuality ever published. By far, most members of U.S. society are heterosexual."