If someone who is living with HIV is taking medication regularly, then the amount of the virus in their system (called the ‘viral load’) will eventually become undetectable. This doesn’t mean that HIV isn’t there, it means that there is such a small amount of the virus that it can’t be detected by the methods used to measure it.
What we know from recent research is that people living with HIV, with an undetectable viral load and no other sexually transmitted infections, have an ‘almost zero’ chance of passing HIV on to someone else during sex. Of course, we can never say never, but the results of the research are very clear.
Having an undetectable viral load is just one of the ways in which people living with HIV are managing the risk of passing HIV on to someone else.
Condoms also are a very effective way of preventing HIV transmission too.
The guy you met has taken responsibility for getting himself tested and is obviously taking his meds regularly to make sure that he stays undetectable.
If you’re seeing him again, and sex is on the cards, have an honest discussion with him and agree on the ways in which you can best prevent him passing HIV on to you.