A few months back, I was invited to speak at Sex Week at the University of Maryland. Amidst such talks as “BDSM on a Budget” and “Deconstructing Gender in Families and Relationships,” there I was, speaking about the negative effects of pornography.

At the end of my talk, a young lady raised her hand and asked my opinion on the claim that porn can enhance romantic intimacy within a relationship. I, as you might have guessed, shared why I thought the claim to be false.

The fact is, many studies show that porn doesn’t complement sexual intimacy with one’s partner. It competes with it. In this post, I’d like to present five ways — all of which are based on scientific data — that show how porn is detrimental to a romantic relationship:

1. People who watch porn have lower levels of sexual satisfaction with their partner.

Drs. Dolf Zillman and Jennings Bryant, in their now-famous porn experiments from the 1980s, found that the more video porn one watches, the more dissatisfied one is with their partner’s physical appearance and sexual performance.

A study published in the Journal of Sex and Marital Therapy reports similar findings. After being exposed to centerfold models from Playboy or Penthouse, test subjects had significantly lower opinions about the attractiveness of “average” people.

2. People who watch porn have lower levels of relational commitment.

The Journal of Social and Clinical Psychology released the result of several studies about the impact of porn on relationships. In one experiment, half of the test group gave up porn for three weeks, and the other half gave up their favorite food, but were allowed to watch porn. Interestingly, those who quit porn showed increased commitment to their romantic relationships at the end of the three weeks.

3. People who watch porn have higher levels of negative communication with their partner.

According to a study published in the Archives of Sexual Behavior, in comparing those who watch porn alone or who watch porn with their partner, those who don’t view any porn at all have lower levels of negative communication with their romantic partner.

4. People who watch porn are more likely to cheat.

Some men have thought — or have even said out loud to their partner — “At least I go to porn to get my needs met. I don’t sleep around.” This hardly serves as a vote of confidence, does it? He’s essentially saying, “If I didn’t have the ability to get off to virtual women, who knows what I would do to real women?” Hmmm, right. #StayClassyExBoyfriend

In one study, for those who don’t watch any porn, their rate of infidelity is at least half of those who had watched porn either alone or with their partners.

Another study found, regardless of how satisfied one feels in their own relationship, watching porn heightens a person’s perceptions that “the grass is greener” somewhere else, and they are more likely to flirt with others and cheat on their partner.

5. People who watch porn have consistently lower views of women.

In the Zillman-Bryant experiments, those who watched more porn showed a radical decrease in support of women’s rights, compared to a control group. Those who watched more porn were also more likely to believe that real women in society should fit the stereotypes of the women they see in porn.

Skeptics may be quick to ask, “But do any of these studies show causation?” That’s a fair question, but somewhat beside the point of this article. While most of these studies only show correlations between watching porn and problems in relationships, this should hardly matter to the porn consumer. No matter how you slice it, if porn makes you a bad lover, or if porn is just the symptom of being a bad lover, or if porn viewing and being a bad lover are both symptoms of the same problem, the verdict about porn is decisively negative.

In the face of claims about porn’s positive effects on relationships, don’t be fooled. You’ll never be good at loving one person well when you’re constantly being entertained by a digital harem.