It is possible for HIV to pass if your performing oral on a penis. HIV can be in the pre-cum or cum and if that gets in your mouth its possible for it to get into your body. It’s not a common way for HIV to pass as HIV does not survive well in saliva.
There can be an increased risk if the person performing has damaged areas in their mouth or if the person who has HIV just had it passed to them and their HIV viral load is very high. The chance of HIV passing when performing oral sex on someone can be eliminated if the person is on HIV medication and has an undetectable viral load or by using a condom.
We do not see HIV passing when people are receiving oral sex, HIV is not in the saliva and does not survive well when exposed to it.
Let us know if you have any more questions or concerns.