Yes Arc, it is safe, BUT...

Most guys are HIV neg. to begin with, but you cannot tell just by looking. When you are HIV positive, almost all of the HIV is going to be in your bloodstream or in your cum, and the total amount of virus in the precum probably isn't worth talking about. So sucking an HIV positive cock is probably about as dangerous as sucking an HIV positive finger or kissing the guy. Now if he blows his load in your mouth, you will be exposed. Your getting infected is another matter. If you have sores in your mouth or bad teeth, or other nasty oral problems, you could be in trouble, but overall, the number of guys who have gotten infected who only do receptive oral sex are few and far between, and incredibly unlucky. Oral sex is relatively but not absolutely safe. But then neither is walking barefoot in a steam room if you have atheletes foot, and just happen to step on some freshly deposited ejaculate. Personally, I prefer sucking dick. Dr. Cutboner