Yes, oral sex without using a condom, vaginal condom or dental dam has a risk of an STI and HIV because of skin-to-skin contact and passing bodily fluids between partners. Oral sex is a high or moderate risk activity for many STIs, including syphilis, chlamydia, HPV and herpes. It’s a lower risk activity for HIV & Hep C. Use a condom or dental dam every time you have sex (anal, oral, vaginal) to reduce the risk of STIs and HIV.