Receiving oral sex is not a realistic risk for HIV infection, so there is no need for worry in that regard.
Other diseases, particularly gonorrhea and chlamydia, are much more easy to transmit via oral sex.
I do not think you need to get tested for HIV. However, an STD screening might be a good idea.
If you are concerned about infecting your girlfriend with STDs, there are several options available. One possibility is simply to avoid penetrative sexual encounters with anyone who is not your girlfriend. Another is to use condoms for all sexual activity.
As far as I am aware, there has only ever been one documented case of HIV infection via kissing.
It seems to me that it has been reasonably long since eating that there would not have been any open wounds in your mouth at the time the kissing too place, and it would also be rather unlikely for this guy to likewise be bleeding from his mouth at exactly the same time - and for him also to have HIV.
I don't think you have any reason to be concerned and I don't think you need to get tested.
I don't know what the nature of your exposure was, but a test 75 days - really anything more than 6 weeks - is going to be pretty much conclusive (90 days is the end of the standard window period).
If you had not produced enough antibodies to test positive by 75 days, then the odds of you seroconverting after that are infinitessimally small, a fact which I am confident that your most recent test will confirm.
In fact, that's how you should look at this: this second test is going to confirm what you already know, that you don't have HIV.
HIV cannot be diagnosed by symptoms. Many people who get infected do experience a short flu-like illness 2 to 6 weeks after infection, but many, many more people experience a flu-like illness because they actually have the flu or something similar.
That being said, unprotected sex should only be attempted with someone you trust implicitly. The old saying is old but nonetheless true: when you have sex with someone, you're effectively having sex with everyone else he/she has ever had sex with. Since you are not a monogamous couple and since she is having sex with other men beside you and since you have no way of knowing whether she is playing safely with them, then it is not a good idea to continue to have unprotected sex with her. The reverse is also true, of course: if you have having unprotected sex with other women, then you are also potentially exposing her to any diseases the other women may have.
There's not much you can do at this point except hurry up and wait. The odds are that these flu-like symptoms are just the flu or a similar non-serious virus. You should plan on an HIV test at 90 days after the last unprotected sexual encounter (you can get a test done at 30 days which will be about 95% accurate and may give you some peace of mind).
Another option, which may not be available or affordable, is a PCR test that is usually used to measure HIV-positive patients' viral load. A PCR test now would be able to tell you if there is any HIV in your body (and if it doesn't find any HIV that would imply that there is no HIV to be found). The downsides of this are that the test is not intended for diagnosis and may not be offered, or may not be covered by insurance, or may have a false positive.
Your risk, from 2 extremely brief instances of unprotected anal penetration, is extremely low.
Since the rectum does not produce fluids of its own, the primary risk of infection for the top is from blood shed by cuts and abrasions in the rectal wall due to intercourse. The brevity of the exposure combined with the lack of certainty of the bottom's HIV status mean that the odds of you getting infected from this encounter are exceedingly small and barely worth worrying about. If you consider that the average estimated risk of infection for a top having an average episode of unprotected anal intercourse with a bottom known to be HIV positive is approximately 1 in 1500, then I think you'll understand that a few seconds of contact with someone who you're not sure even has the virus will be much less risky.
However, you don't want this to become a habit so I would recommend a test at 90 days. As a general rule, everyone who is sexually active (regardless of how careful he or she may be) would do well to get tested every six months just to be sure. Also, less serious STDs like gonorrhea and chlamydia can be much more easily transmitted by this kind of contact, so it would not be a bad idea to get screened for those as well.
How much longer do you have to wait until 6 months?
Because I don't think at this point you will get an answer that completely satisfies your concerns.
HIV tests look for antibodies produced by the body to fight off HIV. If a test is done and there are no antibodies, then there are three possibilities:
1. The person doesn't have HIV. 2. The person has HIV but hasn't produced enough antibodies yet to trigger a positive reaction in a test 3. The person has no functioning immune system and should really be either hospitalized or dead.
It's #2 that is the kicker. Different people produce antibodies at different rates and it will take different people different lengths of time to produce enough so that any random sample of blood will contain enough HIV antibodies to trigger a test.
Practically everyone will have produced enough to test positive by 6 weeks, so the rest of the window period is really to catch as many outliers as possible.
Another factor is the probability of risk. I'm not sure if you're a man or a woman, but in general the average estimated risk of infection from what you describe is somewhere less than 1 in 2,000 for men and about 1 in 1,000 for women assuming the other person was known to be HIV-positive. If their status is unknown, then that throws another variable into the mix that decreases the likelihood.
For me, a negative 3 month test after this kind of encounter would be sufficient to say "No, you're not infected." But I'm not you. If you can hang on until 6 months to get tested to ease your fears, then do it.
Your friend has never engaged in any activities that would conceivably put him at risk. There is no need to worry or get tested.
The deeper issue, of course, is his questioning of his sexuality. If it is at all possible, he should seek out the assistance of a therapist or counselor to talk about his experiences and what the best way for him to work through this conflict in a healthy way.