What are the risks of contracting a sexually transmitted disease if a woman performed oral sex on a man without a condom?
When the mouth and tongue are healthy and uncut, the chance of getting a sexually transmitted infection (STI) through oral sex is quite uncommon, though possible. Sores or scrapes in the mouth present a ready passage-way for virus or bacteria to enter the blood stream. Unless you're 100 percent sure of your partner's clean bill of sexual health, it's a good idea to use protection if any cuts, tears, sores or scrapes are present in the mouth (even tiny sores, like accidentally biting your tounge). Additionally, after you've had your wisdom teeth yanked, a root canal performed, or your dentures re-fitted, it's wise to stay away from unprotected oral sex (even if your partner is STI-free, your dentist would probably advocate treating your mouth gently after any of these procedures).
STIs like gonorrhea, syphilis, Chlamydia, HPV, and HIV can be transmitted through pre-cum or ejaculate. Herpes, especially when cold sores are present, can also be passed on through oral sex. Although these cases are rare, transmission is possible, and if you don't want to gamble with your health you could try using an un-lubed condom or a dental dam during oral sex.
Check out Oral Sex and Herpes — A Triple Header and other related Alice questions linked below to read more about this issue. In the meantime, you likely don't need to worry. Although STI transmission is possible through oral sex, it happens rarely. Perhaps with this information you could change your signed name from "worried" to "wary" or "wise"?Alice!