Coinfection with other STDs can increase risk of transmission of HIV
by up to 2 - 5 times. (Per CDC, San Francisco AIDS
Fact: One can never be certain whether or not one's partner is coinfected w/ HIV and another std. (given)
Conclusion: If the partner has HIV, risk of oral sex in relation to HIV infection ranges from 1 in 2000 to 1 in 10,000 for this single occurance. Therefore, chance of infection is low, but certainly not zero.