You can get an STD like herpes or the HPV virus without even having sex! Some STDs, like the viruses that cause genital herpes and genital warts, can be passed to another person by "skin-to-skin contact." This is when your genitals (penis, testicles, vagina) or the skin around them touches someone else’s genitals.
Sometimes a person with genital herpes or warts will have blisters, bumps or sores near or on their genitals, but sometimes they won’t have any at all! Genital herpes and warts can still be passed to someone even if they don’t have any herpes or warts that you can see. Sometimes the blisters, bumps or sores come and go but the virus still stays in the body. When this happens, it’s still possible to pass the STD to another person.
Condoms are great at helping to lower chances of passing some STDs like Gonorrhea, Chlamydia and HIV. But, you can still get some STDs "skin-to-skin," like herpes and warts, even when you use a condom. Because of this, it’s important to talk with your partner about blisters, bumps or sores either of you have had in the past, avoid touching them or having any kind of sex if you see them, and get tested for STDs at a clinic.