Source: Irina Bg/Shutterstock

Many people prefer porn made with or by their partners. Multiple men have told me that their adult images and videos of choice are those they’ve made with their wife or girlfriend. They say, “It’s someone I know and love. I know she’s not faking"; “I know she’s turned on because I was there, and because I know her and what she sounds like"; “I love her, and seeing her turned on and happy is a far greater turn-on than watching a porn star I don’t know.”

Other men simply prefer amateur images in general, as opposed to those of professional models, as it creates and supports the perception that the models are enjoying exhibiting themselves and being sexual. There’s the suggestion that woman is a “girl next door” — someone whom the viewer can imagine themselves actually meeting or being sexual with.

But what happens when a guy tells his ex that he got rid of their homemade porn, but didn’t? Or when a man entices a person into sharing nude photos and then shares them online, without that person's consent? Or when a man uses hidden cameras to capture intrusive, privacy-violating images? That moves us into deeply unethical, harmful territory.

There are new laws and growing public outcry over “ porn” websites, where people post such pictures in efforts to humiliate, , and expose former lovers. I know women who have suffered tremendously after having pictures posted without consent on such sites. In several cases, the women approached website operators to request their images be taken down, and then experienced horrific attacks and slut-shaming.

The United States Marines Corps now faces a scandal in which active and retired members have shared nude pictures of female fellow Marines in secret Facebook groups. News reports have referred to it as a “nude photo scandal.” But let’s be clear: The great majority of these pictures were shared on these sites without consent. These aren’t merely “nude photos"; they are nonconsensual revenge porn images, even if some didn't start out that way.

The great majority of these types of pictures are in fact shared consensually — at least, at first. When we are turned on, , and excited about a new lover or lover-to-be, many people now employ explicit picture sharing as a part of courtship. The overwhelming majority of couples experience this activity as a positive part of their sexual expression, and it often correlates with greater sexual satisfaction. Unfortunately, we often send these pictures without a clear “pre-nuptial” agreement about what’s going to be done with those pictures, in the moment and maybe after a relationship ends.

Many people now possess nude or explicit images of former flirtations or partners. The ethical way to handle such images is to ask a partner permission to keep the materials for your private use, even after you break up or end a relationship, or to agree, at the moment when the images are shared, how they will be treated by the recipient. They have to trust you enough to believe that you can have the materials and never put them on a revenge porn website or share them with other people. And ethical men should never post explicit pictures of anyone, other than themselves, without explicit permission.

Today, the Internet is plagued with nude photo scandals, from Celebgate, to the pictures circulating of the current First Lady, to the recent Marines Corps scandal. Guys put homemade porn up on the web for a variety of reasons. As with most things involving , relationships, and , it isn’t a simple black-and-white issue, and we cannot assume that men post these pictures simply from misogynistic motivations. The real reasons why men post such material online are complex, nuanced, and based on context, and we have to understand and acknowledge these reasons in order to address this problem effectively.

Source: Wikimedia Commons

Following are some of the reasons I've heard for why men choose to post revenge porn, from men including my patients:

To show off to other men (and himself) what a stud he is — that he not only got a hot girl to have sex with him, but she let him film it. This is sometimes called candaulism, after the Greek king Candaules, who showed off his naked wife to an advisor, Gyges, and then lost his kingdom to Gyges when the wife found out.

To get revenge on a woman for breaking up with him and hurting his feelings. Rather than admitting and dealing with his feelings, he lashes out and tries to take her down a peg. Some men cross extreme lines, "doxxing" the victim and sharing her name and personal information as well.

To be one of the “cool guys” who post such images. There’s a lot of in some online communities. Men want to be cool, and they want to share their porn with guys who have already shared with them. These men value being seen not just as a “taker,” but to give back. (It’s strange, perhaps, to imagine this positive value involved here, where it causes harm.)

Because the guy just doesn’t understand how small the world has gotten and how easy it is for such material to be identified, and traced back to the woman.

Because the guy is angry at all women, and wants to take them down. I actually think this is rarer, but it certainly seems present in some of the highest-profile revenge porn cases. Within the Marines, it is certainly worth speculating that some of these men were motivated by at women’s increased role and acceptance in the Corps.

Because the guy thinks the woman might actually be excited and turned on by the man sharing her picture. Many men believe that they would be turned on by the idea of a group of women looking at naked pictures of them, and they truly believe that a woman would experience this the same way — without understanding that women’s sexuality is typically treated quite differently by society.

I invite men who nonconsensually share nude or explicit pictures of their partners to do some real work examining why they do it and what they get out of it. When men engage in revenge porn, they make it harder for women to express their sexuality in a healthy, consensual, safe way. It also feeds a frightening, paranoid, sex-negative, and distrustful view of men, and of the world.

Men can be ethical and responsible and share sexy pictures with partners and flirtations. But they have to learn to keep it to themselves unless they have a woman's explicit permission to share. These scandals will continue until we teach and encourage men and women to have ethical conversations with each other, and with their friends, about sexual integrity around nude and explicit images. Our strategies to understand and address these issues must be nuanced and complex. Simplistic answers and responses will be unsuccessful, as they do not reflect the complexity of the motivations behind nonconsensual photo sharing.

One last update: The Marines photo scandal has now expanded into gay sites, where men have shared nude pictures of other military men. This cannot simply be blamed on misogyny, but must be understood and addressed as an issue involving sexual integrity, self-awareness, relationships, and emotional , along with the growing technological capability to engage in behavior for which we haven’t developed adequate .

This post is excerpted from my recent book, Ethical Porn for Dicks: A Man's Guide to Responsible Viewing Pleasure, which encourages men to develop integrity and responsibility around their use of pornography.

Follow David on Twitter: @drdavidley