Safe sex will always be important regardless of whether you are HIV-positive or not. The reason is simple: HIV is not the only STD people are vulnerable to, which means that HIV-positive individuals can also be infected with other STDs. Also, if these other STDs are transmitted to a HIV-positive person, their existing HIV can make some of these STDs substantially worse.

Reference: https://www.verywell.com/practicing-safe-sex-when-both-partners-have-hiv-3132966/