All in all, oral sex is safe sex:  not completely free of risk, but with very low chance of HIV and other STDs compared with vaginal or anal sex. There have been very few scientifically proved cases of HIV transmitted oral to penis, maybe none at all. Based on how some men believed they were infected -- which often is mistaken -- CDC once calculated a risk of one chance in 20,000 if the oral partner had untreated HIV. That's equivalent to receiving BJs by infected partners once daily for 55 years before transmission of the virus might be expected. And HIV is rare in women in the US, even among the most sexually active (like sex workers), so it is very unlikely your partner has HIV. In other words, zero risk for all practical purposes.

The main STDs from oral sex are gonorrhea, nongonococcal urethritis (often due to normal oral germs), and herpes due to HSV1. With a female partner, the chance of any of these is probably under one chance in a few thousand for each event. We advise against STD testing in this situation unless symptoms develop (penile discharge, painful urination, penile sores).

I doubt this risk would rise even if an infected male had ejaculated in the oral partner's mouth -- even a few minutes earlier. Natural clearance by swallowing probably would reduce the amount of virus very rapidly to very low levels. Therefore I would consider the risk no different even if the oral partner had recently performed the same service for another male.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

Even with higher risk sexual practices -- e.g. no condom at all -- in general we advise against testing after any single exposure, except in especially high risk situations (e.g. if you learn for sure a partner had a transmissible STD). Rather than testing after every event, a smarter approach is to plan on regular testing at various time intervals -- like a year, or 3 or 6 months depending on frequency of new events. And of course if symptoms of possible STI show up.

I don’t know she probably does have an std she is very promiscuous. 

At any point in time, even the most sexually active ("promiscuous") women do NOT have a transmissible STD at any point in time (not counting HPV, which you can assume exists in all sexually active people, including yourself).

No matter if her gums or bleeding etc or whatever other scenario there’s never been a documented case.

That completes the two follow-up comments and replies included with each question and so ends this thread. I hope the discussion has been helpful.