What should my boyfriend do if he thinks he has stis?

You both see a doc: If he has symptoms of an sti, and you're having sex, then you should both be evaluated. Sometimes a diagnosis can be made in one partner and not the other, in which case you should both be treated. And at that point, both of you need to contact your previous sexual contacts to see if they're having symptoms and need to be treated, as well. If there's a disease, it camefrom somewhere, right?