A couple of days ago I fooled around with someone I know that has slept around with a lot of women. We didn't get very far because he didn't have a condom. What worries me is he rubbed his penis against my vagina and he had a lot of precum. I wore underwear the entire time but what worries me is the possibility of his precum still coming in contact with my vagina. Am I at any risk from this?
Any time HIV infected fluids (like semen or pre-cum fluids) come into contact with your mucous membranes (like the lining of your vagina), there is the possibility of transmission. The most common routes of sexual HIV transmission are through vaginal, anal, and oral sex. There is no direct evidence of transmission through other forms of sexual contact (grinding, mutual masturbation, kissing, etc.). So, even though the possibility of transmission exists, it is highly unlikely.