Animal sexual behaviour however, is proving to be false as, "most hormones don’t influence behaviour directly. Rather, they affect thinking and emotions in variable ways (Azar, 40)." There is much more involved in sexual behaviour in the mammalian animal than oxytocin and vasopressin can explain. It is often assumed that animals do not have sex for pleasure, or alternatively that humans, pigs, bonoboes (and perhaps dolphins and one or two more species of primates) are the only species that do. This is sometimes stated as "animals mate only for reproduction". This view is considered a misconception by some scholars. Jonathan Balcombe argues that
Casual sex to swinger couples who are already in committed relationships and are only seeking compatible friends with whom they can engage in recreational sex. Recreational or social sex refers to sexual activities that focus on sexual pleasure without a romantic emotional aspect or commitment. Recreational sex can take place in a number of contexts: for example, in an open marriage, among swingers (where sex is viewed as a social occasion), or in an open relationship. A "hookup" (colloquial American English) is a casual sexual encounter involving physical pleasure without necessarily including emotional bonding or long-term commitment; it can range from kissing