The other day, I met a guy and we fooled around in the back of his car. He told me he got two tests done that were HIV negative and I want to believe him, considering he provided me with information that would be hard to come up with on the spot (e.g. what they ask you, what they do during an STD test, etc.). Anyway, I sucked on his 'ball sack' for a good 10 seconds and then he sucked on mine. Now I don't remember seeing any pre-cum anywhere and he never ejaculated on me or near me.
Should I be worried?