Editing Open relationship (section)

==== Sexually transmitted infection ====
{{Main|Sexually transmitted infection}}{{See also|safe sex|polyfidelity}}
Any sexual contact outside of a strictly [[monogamy|monogamous]] or [[polyfidelity|polyfidelitous]] relationship increases the possibility that one member of the group will contract a [[sexually transmitted infection]] and pass it into the group.

Neither [[Birth control#Barrier|barrier device]] use (such as [[condom]]s) nor more vigilant [[STI testing]] and vaccination can fully eliminate such risk,<ref>{{Cite book |last1=Hatcher |first1=Robert Anthony |url=https://books.google.com/books?id=txh0LpjjhkoC&pg=PA297 |title=Contraceptive Technology |last2=M.D |first2=Anita L. Nelson |publisher=Ardent Media |year=2007 |isbn=9781597080019 |pages=297–311 |language=en |archive-url=https://web.archive.org/web/20170918185600/https://books.google.com/books?id=txh0LpjjhkoC&pg=PA297 |archive-date=18 September 2017 |url-status=live}}</ref> but can reduce the statistical increase attributable to nonmonogamy. Nevertheless, using data from the 2012 National Survey of Sexual Health and Behavior, Levine et al. (2018) found that individuals in open relationships reported more condom use in both vaginal and anal intercourse compared to monogamous couples.<ref name=":0" />

The development of [[Pre-exposure prophylaxis|PrEP]] has led to a decrease in risk for HIV infection by as much as 92%.<ref>{{Cite journal |last=Holmes |first=David |date=28 July 2012 |title=FDA paves the way for pre-exposure HIV prophylaxis |url=https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61235-5/abstract |journal=The Lancet |language=English |volume=380 |issue=9839 |pages=325 |doi=10.1016/S0140-6736(12)61235-5 |issn=0140-6736 |pmid=22852138|s2cid=7096469 |url-access=subscription }}</ref> If both partners are on PrEP, risk of HIV infection is diminished, even if there are multiple partners.