Oral sex is not very likely to end up in HIV transmission, regardless of whether you’re giving or receiving.
Oral sex has an extremely low chance of HIV transmission, whether you’re the one giving head or getting head.
The fact is, most HIV transmission happens when guys have condomless anal or frontal (vaginal) sex, not oral sex.
If you are giving head, there is still a very, very small possibility that cum or other fluids could enter through the mucous membranes in the mouth or throat.
It’s also good to be cautious if you have a canker sore or cut inside your mouth, and to avoid brushing or flossing your teeth at least 30 minutes before or after giving head or rimming someone. If things get rough and any skin breaks, take a break from oral sex until everyone’s healed up.
If you are getting head, the chance of transmission is insignificant. Saliva cannot transmit HIV.
If the sex you want involves a lot of oral sex, it is important to maintain good oral health. If you suck dick, get your throat swabbed as part of regular STI testing.