Qwestion...

SM (Sadism and masochism)
Sadism is the sexual or social pleasure or gratification in the infliction of pain and suffering upon another person. The word is derived from the name of the Marquis de Sade, a prolific French philosopher-writer of sadistic novels, plays, and a unique philosophical discourse that championed the infliction and reception of extreme pain as an art form that to him was both sublime and beautiful. The counterpart of sadism is masochism, the sexual pleasure or gratification of having pain or suffering inflicted upon the self, often consisting of sexual fantasies or urges for being beaten, humiliated, bound, tortured, or otherwise made to suffer, either as an enhancement to or a substitute for sexual pleasure. The name is derived from the name of the 19th century author Leopold von Sacher-Masoch, known for his novel Venus in Furs that dealt with highly masochistic themes.
Sadism and masochism, often interrelated (one person obtaining sadistic pleasure by inflicting pain or suffering on another person who thereby obtains masochistic pleasure), are collectively known as S&M or sadomasochism.
The words are now commonly used to describe personality traits in an emotional, rather than sexual sense. Although it is quite different from the original meaning, this usage is not entirely inaccurate. There is quite frequently a strong emotional aspect to the sexual desires, taking the form of a need for domination or submission—the desire to control another, or to be controlled, as opposed to a simple desire for pain (which is technically known as algolagnia).
The biology of S&M


Pain, violence, sex and love all are associated with the release of a variety of hormones and chemicals within the human body. Furthermore, humans have been shown to exhibit sympathetic responses in their bodies while watching, hearing, or imagining such experiences.


Endorphins are released by pain experiences and can be perceived as pleasurable and possibly psychologically addictive. It is due to this same release of endorphins that people can become addicted to self harm. In this way, the acts of self harm and engaging in masochistic behavior can be similar in function though most would agree, not in causality.

Brain chemicals such as serotonin and melatonin can be affected by emotional or stressful experiences.

Epinephrine and norepinephrine are released during stressful or painful experiences, and can cause a pleasurable 'rush'.

The effects of S&M on body chemistry possibly reinforce the behavior and therefore might create psychological states that seek to further such behavior.

{SM}就係性虐侍遊戲,例如: 用繩或鐵鏈將對方縛著後,才與她(他)做
愛等.