Public health types are always agonizing about oral sex. Should we say it's dangerous or not? Now, Swedish researchers have shown that lots of oral sex with an HIV-infected partner may actually be protective against the virus.
The study, published in the (expensive, subscription only) AIDS journal and helpfully summarised by Aidsmap suggests that men who give lots of blow jobs to their HIV-positive partners develop antibodies specific to that partner's virus, protecting themselves against infection. The more virus their partner has kicking around in their semen, the higher the concentration of specific antibodies, and the protection seems to last for quite a while too. None of the men became infected over the course of the study, even though their partners were not all on treatment.
You certainly learn something new everyday! (I always thought it was god for my health...)