There seems to be a widely shared belief that anyone involved in an "open" relationship is infected with all sorts of STDs. The assumption seems to be that if you aren't monogamous, you're a promiscuous disease spreader, right? Not so fast. The reality is actually far more complex than this, and the risks of “open” and “closed” relationships may not be as different as they are assumed to be.
The scientific term for “open” relationships is negotiated nonmonogamy (NN), a term that describes all relationship arrangements in which people are free to pursue sexual partners outside of their primary partnership. This can obviously take many forms and you may hear these relationships referred to by a number of different labels (e.g., swinging, open marriage, etc.). However, NN is not the same as polyamory, an approach to relationships in which people have multiple romantic partners simultaneously and the focus of each relationship extends beyond sex.
While it might seem like people in NN relationships would be at a higher risk for getting STDs than people who practice monogamy, this belief rests on the assumption that monogamous partners never stray, and we know that’s not true! For instance, research consistently finds that 20 to 25% of married couples have had sex outside of their relationship at some point in time.1 If anything, these numbers are probably an underestimate, given that they do not take into account people who are unwilling to admit that they’ve cheated.
Here is the problem: when someone in a monogamous relationship cheats, it is more likely than not that they will fail to use condoms. A recent study found that people who cheat were significantly less likely to use condoms with partners outside of their primary relationship than people who practice NN (the percentage using condoms was 48% vs. 66% for vaginal intercourse and 32% vs. 49% for anal intercourse, respectively).2 Not only that, but cheaters were less likely to discuss their sexual history and disease status, were more likely to have sex under the influence of drugs and alcohol, and were less inclined to tell their primary partners about those sexual encounters. Research on other types of nonmonogamous relationships has yielded similar findings. For example, people in “friends with benefits” relationships have more consistent condom use and are more likely and to discuss outside sexual encounters with their primary partners than people in romantic relationships.3
Altogether, these findings tell us that it is misleading to assume that nonmonogamy is always risky and that monogamy is always safe. The reality is that all relationship arrangements carry some degree of risk. Of course, monogamy is still the safest arrangement in terms of reducing one’s likelihood of contracting STDs, but only if you can trust that neither you nor your partner will ever stray. However, complete and lifelong fidelity to one person is not realistic or feasible for some people. Keep in mind that NN is not necessarily safer, because although condom use tends to be higher, it is still far from perfect. The key is to find the right type of relationship for you and to maintain an open and honest sexual dialogue with your partner(s).
1Luo, A., Cartun, M. A., & Snider, A. G. (2010). Assessing extradyadic behavior: A review, a new measure, and two new models. Personality and Individual Differences, 49, 155-163.
2Conley, T. D., Moors, A. C., Ziegler, A., & Karathanasis, C. (2012). Unfaithful individuals are less likely to practice safe sex than openly nonmonogamous individuals. Journal of Sexual Medicine, 9, 1559-1565.
3Lehmiller, J. J., VanderDrift, L. E., & Kelly, J. R. (2012, July). Sexual Communication, Satisfaction, and Condom Use: A Comparison of Friends with Benefits and Romantic Partners. Paper presented at the International Association for Relationship Research Conference, Chicago, IL.
Dr. Justin Lehmiller - Science of Relationships articles | Website/CV
Dr. Lehmiller's research program focuses on how secrecy and stigmatization impact relationship quality and physical and psychological health. He also conducts research on commitment, sexuality, and safer-sex practices.