You have full access to this open access article. Male HIV serodiscordant couples have diverse relationship agreements regarding sex outside the relationship. We examined the relationship agreements as described by male HIV-negative partners in HIV serodiscordant relationships in Australia, Brazil and Thailand participating in a multi-year cohort study.
At baseline, When considering HIV transmission risk for HIV-negative men in serodiscordant relationships, greater focus needs to be placed on sex that is occurring outside the relationship and the agreements that facilitate this. The last decade has seen substantial changes in HIV prevention and care due to improved understanding of the benefits of early treatment for both the health of the individual living with HIV [ 1 ] and the prevention of onward HIV transmission [ 2 , 3 , 4 ].
HIV serodiscordant couples have been seen as an important context of HIV transmission [ 5 , 6 ] as anal sex presents a high risk of HIV transmission [ 7 ] in the absence of protective behaviour. Male couples have diverse types of relationships, and it is common to have additional sexual partners outside of the primary relationship [ 13 , 14 , 15 , 16 , 17 ].
This behaviour may be regulated through the use of explicit, spoken relationship agreements which may take multiple forms, and is distinct from sexual arrangements which relate to implicit understandings of what is allowed in the relationship [ 18 ]. Where couples do agree that sex can occur with other partners, agreements can cover sexual activity that may occur together, apart, or both. Sex outside the relationship can also occur in the absence of an agreement [ 19 , 20 , 21 , 22 ].
The agreement about other sexual partners may also change, often beginning with an initial period of sexual exclusivity and moving to a relationship that includes other sexual partners [ 21 , 22 , 23 , 24 ].
