With any kind of sexual contact there are always risks. With oral there are more risks if you're the person doing the sucking. If you have recessed gums, gingivitis(mild gum disease)or any cuts or abrasions on your gums or the walls of your mouth or throat you can catch anything from gonnarhea, hepatitis, herpes, chlamydia, to HIV. The suckee can get those things too if they get nicks or cuts on their dick from the suckers teeth although you can still catch any of those things even if there's no injury. To answer HB's question, rimming is a very easy way to contract hepatitis or any other bacteria that might be in someone's fecal matter. If you perform any kind of oral sex on someone unprotected, it's a good idea to rinse with listerine or hydrogen peroxide to reduce the risk of catching anything, but it doesn't eliminate it though. The person getting sucked should wash also afterwards(that should be a no-brainer!!) And don't knock condoms til you've tried them, just make sure to use unlubed ones with some water based lube on the inside(it feels pretty good). Have fun and play safe guys.