Thanks for the question. I assume your initial STD screen included an HIV test and was negative.
There is a window period for the HIV test of 1 to 3 months. So if the HIV screening was done within this period from the last high risk exposure encounter, then you may need to consider repeating the test.
In general, mutual masturbation (with hands) should be safe but oral sex does carry a low risk of transmission.
This is particularly if there are ulcers or cuts in the mouth or genitalia, bleeding gums and contact with blood and in individuals with a high HIV viral load.
In such situations, you should consider repeated screening for HIV.
Remember that prevention is always the key, so it is important to use condoms and have a monogamous relationship with a single partner to limit the risk.
