If you are male then yes it is.
spit it back out You need to specify your gender. Are you a female and can't feel the semen enter your vagina, or are you a male and can't feel the semen travelling along your penis?
Unhealthy semen is usually produced by people who can't use the correct spelling of 'does' ! If you can't spell it - you shouldn't need to know about it !
You need to eat more pineapple.
To answer your question directly, no, "black stuff" in your semen is not a symptom of HIV infection. To address the real problem here, if you have "black stuff" in your semen, you need to go to your doctor. Immediately. Like, now.
If he ejacuated, he had an orgasm. If you do not know if he had an orgasm, the man needs some help with sex. If this has to do with semen entering, he does not need to ejaculate to have semen enter. Over all, you should know, if not, find a new man!
There is no way you can tell if your wife has semen in her panties and you need to study up on sexual education. Just like men, women discharge and it can be clear to yellow in color. Be very wary of accusing your wife of cheating on you by mistaking discharge for semen.
We feel like we need to be loved on
As many as what a breeder needs. Bulls don't produce semen that need to be collected like with cows that produce milk. A bull can fill thousands of straws per year if need be, depending on the demand for straws from that particular bull.
They feel like they need to find them in order to feel like they belong again.
If your brakes feel like they are pulling you should get them checked out. These brakes may need to be replaced.
A urologist.
You need to clean the pipe!