Question: If my partner and I both have herpes, is a condom necessary during sexual intercourse when neither are in an outbreak?
The answer isn't as straight-forward as you might think. If you both have the same type of genital herpes (say, HSV-1 or HSV-2) then there is no worry about being sexually active. There could be an issue if, say, one of you has genital HSV-1 while the other has HSV-2.
Let me give a little background about this: there are two primary types of herpes simplex virus, or HSV, we talk about. HSV-1 is what you primarily think about with cold sores of the lips/face, and is something most people acquire as an oral infection at some point (usually through kissing). HSV-2 is the type of the virus you most often think of with genital herpes and sexual transmission. These two strains of HSV are very similar, with the chief difference being that one prefers oral/facial tissue while the other is more likely to do its thing below the waistline. One isn't really better or "worse" than the other.
It's possible to have either type as an oral or genital infection, though, and HSV-1 is fairly often found with genital infections (it's possible, but pretty uncommon, for HSV-2 to set up shop as an oral infection). SO....
I consulted an clinical expert in HSV as to how best to frame my response. She suggested that if you're uncertain which types of genital HSV you have, get specific antibody testing to confirm. If by some chance you and your partner have different types of genital HSV, it still doesn't mean it's a big deal but you probably would be cautious during times you suspect there are symptoms.
Hope this helps.