There's not necessarily a perfect time to tell your partner that you have an STI, because every relationship progresses at a different pace, but you should absolutely do it before having sex, Lilla says. "Some people prefer to have this conversation right away when they begin dating someone, and may not want to be with someone who judges them for having an STI," she says. "Other people do not want to be judged, and may feel embarrassed or even guilty, so they might prefer to wait until they get to know someone and have established some trust before discussing it." But if you wait to share your STI status after you've already had sex, then it can make your partner feel betrayed, Lilla says. Although you might be comfortable having sex and using condoms as a barrier method to reduce the risk of STI transmission, your partner might not be if they know you have a particular STI — and that's okay, but it warrants a (sex-positive and shame-free) conversation to figure out where everyone's boundaries are.