Anytime there's skin-to-skin genital contact or an exchange of bodily fluids, there's a risk of STI transmission. The following are spread through skin-to-skin contact: HPV, herpes simplex virus (HSV), trichomoniasis, syphilis, and molluscum contagiosum. The following are spread through bodily fluids: HPV, HSV, trichomoniasis, HIV, chlamydia, gonorrhea, and hepatitis B.