
Because all “sex sin” leads to addiction, extramarital affairs, prostitution and sado-masochism are all viewed as symptoms of sex addiction by Porn-Free.org and many other sites.
For instance, the Sexual Addiction and Recovery Web site lists all three as addictive behaviors. Pornography, masturbation and fantasy are both listed as "building block" behaviors toward addiction. About fantasy, the site said:
"The mind is where all the behaviors start. The fantasy may be about a sexual act or it may be about a person. Another term that could be used is 'daydream.' The desires and thoughts about the behavior start in the mind before an addict engages in any other act of the addiction."
The Sexual Addiction and Recovery site also warns that sex addicts not in recovery have two possible destinations in life: the morgue or prison.
According to those who say sex addiction exists, any behavior can become compulsive. The sex addict engages in behavior he or she knows to be destructive but can't control. We know that alcohol addiction is an illness, and sex addiction is no different. Sex addiction takes over the life of the addict, breaks up marriages and prevents addicts from having healthy relationships. Some proponents of this point of view believe that the problem of sex addiction, like other addictions, has a spiritual component and requires a spiritual cure.

Studies differ, with 15 to 50 percent of men engaging in extramarital sex and 20 to 26 percent of women engaging in extramarital sex.
Dr. Alfred Kinsey found that 69 percent of white males had been to a prostitute at least once.
Kinsey also found that 55 percent of women and 50 percent of men responded erotically to being bitten. In 1983, Walter Lowe found that 11 percent of men and 17 percent of women reported trying bondage and that 5-10 percent of Americans engage in sadomasochism at least occasionally.
Laumann et al found that 54 percent of men and 19 percent of women think about sex everyday or several times a day.
Critics of the concept of sex addiction say that although some people may engage in destructive sexual behavior, being "out of control" is just a metaphor for feeling out of control and each person is responsible for his or her actions. Further, society has historically been too negative toward normal sexual behavior, and there is still some disagreement over which sexual behaviors are compulsive and which ones are normal. Also, expanding the definition of addiction this way is inappropriate and renders the term meaningless.