Sexual arousal can also be experienced from foreplay and flirting, and from fetish or BDSM activities, or other erotic activities.Most commonly, people engage in sexual activity because of the sexual desire generated by a person to whom they feel sexual attraction; but they may engage in sexual activity for the physical satisfaction they achieve in the absence of attraction for another, as in the case of casual or social sex.Joan Roughgarden, in her book Diversity, Gender, and Sexuality in Nature and People, postulates that this applies equally to humans as it does to other social species.She explores the purpose of sexual activity and demonstrates that there are many functions facilitated by such activity including pair bonding, group bonding, dispute resolution and reproduction.These include erotic asphyxiation and self-bondage. The potential for injury or even death that exists while engaging in the partnered versions of these fetishes (choking and bondage, respectively) becomes drastically increased in the autoerotic case due to the isolation and lack of assistance in the event of a problem.Sexual activity can be consensual, which means that both or all participants agree to take part and are of the age that they can consent, or it may take place under force or duress, which is often called sexual assault or rape.It releases tension, elevates mood, and may create a profound sense of relaxation, especially in the postcoital period.
Some non-conventional autoerotic practices can be dangerous.
At times, a person may engage in a sexual activity solely for the sexual pleasure of their partner, such as because of an obligation they may have to the partner or because of love, sympathy or pity they may feel for the partner.
A person may engage in sexual activity for purely monetary considerations, or to obtain some advantage from either the partner or the activity.
A man and woman may engage in sexual intercourse with the objective of conception.
Some people engage in hate sex, which occurs between two people who strongly dislike or annoy each other.