Marty Ralph Klein (born 1950) is an American sex therapist, author, educator and public policy analyst.

Klein has spent his career supporting the healthy sexual expression of men, women and couples in a wide range of ways.

He believes that public policy relating to sexuality should be driven by scientific data rather than emotion, "tradition" or popular but untrue myths.

He has been a participant in various state, federal and international court cases dealing with the First Amendment, obscenity, censorship and "harmful to minors" laws.

[2] Klein was trained in the doctoral programs of two different branches of sociology: the first was survey research, the use of statistical analysis to gather data about human behavior in order to understand, correlate and predict it; the second was ethnomethodology, which is the study of how people create meaning as a prelude to creating orderly social interactions and predictable social institutions.

These women's explanations surprised him: they didn't want to use birth control because they were afraid their partner would think they were a slut, or that they had actually planned to have sex with a stranger they'd just met at a bar.

[4] Communication is the key to satisfying relationships; things like new positions or removing pornography from a home without your partner's consent is generally not helpful.

[5] Klein told the Commonwealth Club that what most adults want out of sex is a combination of "pleasure and closeness," and he encourages people to pay more attention to these, rather than to performance anxiety or how they look.

"[7] In an interview with Chip August for Personal Life Media Klein stated, "I think Oprah has single-handedly launched the victim industry in this country," adding that society is now infantilizing women by saying that they are unable to make decisions for themselves, that they are tricked into drinking at parties, that they can't control whether they get drunk or create circumstances of vulnerability.

Host Steven Novella asked Klein if anti-pornography groups are trying to justify their opposition by citing health concerns or were just confused about the science.

He observed that couples that don't have sex anymore are quicker to fight about pornography rather than have a meaningful conversation about problems in their sexual relationships.

In addition, he explained that consumer products based on fantasy are mostly about what people want to see, not necessarily what they want to do or experience, as both men and woman fantasize about things they would not do even if given the chance.

In all cases, Klein said, it is important to listen, remain calm and make sure the child knows they are not a bad person for having sex questions and that they can ask the parent anything.

[17] Klein's concerns with the concept of sexual addiction are that it appears to lend scientific credibility to it and implies that "sex is dangerous.

"[18][19] Twelve-step programs for sex addiction are of limited value because they are typically self-referred for a problem that any lay person can diagnose.

"[15][20][21][22] Michigan passed a law in 1999 criminalizing the distribution of "sexually explicit" material on the Internet fearing it could fall into the hands of minors.

Plaintiffs, which included Marty Klein, challenged the law arguing that it violated the First and Fourteenth Amendments, and it was ruled unconstitutional in June 2001.

The case was heard in October 2010, and in April 2011 the Bill was signed into law, but with the stipulation that it could only be enforced if the "harmful material" was knowingly distributed to a minor.