The chance of getting HIV from cum in the mouth and swallowing it are very low. Semen can have the virus, yes, but the digestive juices in mouth, throat and stomach will mostly likely make it inoperative. If you have bleeding or a sore, I would forgo taking the cum. Have him wear a condom. I know a cock with a condom isn't very appealing but you can still get the texture if he wears a high quality sheer condom.
Otherwise, forget the condom and enjoy his cock, and his cum!
I say 'down the hatch' and enjoy