 Oral sex isn't the riskiest activity. But it's not 100% safe either. It's up to you to decide what your limits are and what's safe enough for you. Oral sex is significantly less risky than unprotected sex.
Using a condom for oral sex is the safest. A little flavored lubricant or honey (or any food without oils) can spice things up. Oral sex is safer without ejaculation. But pre-cum contains HIV, too. Be aware of the state of your mouth. Bleeding gums or cuts can increase the risk of infection. In the absence of blood and open sores, rimming (oral-anal contact) is not very risky for HIV. But you can get hepatitis, gonorrhea or other sexually transmitted diseases. | 
