Your initial two forum questions five years ago (threads 4035 and 4043) included detailed discussions of oral sex and STD/HIV risks, but primarily centered on fellatio and risk to the oral partner. I'm happy to expand on that discussion.

It is true that general advice about oral sex often doesn't distinguish between fellatio and cunnilingus, and often not between risks from insertive versus receptive exposure -- e.g. performing versus receiving a BJ or oral-vaginal exposure. Also, there is no rigid definition of "safe sex". Ideally, it would be better to refer to oral sex as "safer" sex and not always "safe". There also are differences between the various infections.

No oral sex event is entirely free of STD/HIV risk, but for HIV almost all exposures can be considered nearly zero. There has never been a scientifically proved case of HIV acquired by oral to penile transmission. As we discussed in your first two threads, CDC has calculated that if the oral partner has HIV, the penile partner has one chance in 20,000 of being infected (equivalent to receiving BJs by infected partners once daily for 55 years before transmission might be likely). For the oral partner in fellatio, the risk if the penile partner has HIV was calculated at 1 in 10,000 (27 years). Even these near-zero risks may be over estimates:  they're based on how infected people thought they had been infected, which often is mistaken. For cunnilingus, there has never been a proved case of HIV transmission in either direction; the fellatio calculations can be considered the maximum risk for such exposure.

Continuing with fellatio, gonorrhea is fairly commonly transmitted in both directions. Chlamydia is not:  as Dr. Hook said in one of your earlier threads, it rarely infects the throat and is even more rarely transmitted from the throat. In addition to gonorrhea, insertive exposure -- receiving a BJ -- primarily risks herpes due to HSV1 and nongonococcal urethritis (NGU), which usually has no known exact cause and likely results from exposure to entirely normal oral bacteria. As for your closing comment, it is likely the oral partner is at greater risk of gonorrhea or HIV if there is ejaculation in the mouth than without it.

Cunnilingus is very low risk for both partners and for all infections. As noted above, there has never been a proved case of HIV transmission -- which doesn't mean zero risk, but obviously it's very low. Dr. Hook was one of the investigators on one of the few studies of gonorrhea, which reported extremely low risk for the oral partner. Cunnilingus can be considered risk free for chlamydia. In theory, it can be a herpes risk -- for the vaginal partner with HSV1 if the oral partner has oral herpes; and for the oral partner if the vaginal partner has HSV2. However, herpes is extremely rare for any single exposure. All in all, most experts consider such protections as dental dams (or a sheet of plastic wrap) to be unnecessary.

HHH, MD

That concludes this thread. Stay well and keep safe.