It's hard to know if this is herpes without a test- so it's important to get that. If it is herpes, it could have been something he picked up during the break up- herpes can lay dormant in the system and most commonly spreads during an outbreak. Does he have any sores? He doesn't necessarily have to have them to spread it, but a majority of the time, that's how it spreads.
Best of luck at your appointment today- let us know how you are doing.