My girlfriend has Hsv-1 and 2 and is currently not on antiviral medication, if she is not having a breakout how much of a risk is engaging in oral sex both ways? How effective would using dental dam for oral sex and condoms for vaginal sex be?
The risk is low for oral sex but not zero. You have a greater chance of contracting hsv1 from receptive sex than hsv2 from giving oral sex. Hsv2 is rarely contracted orally as is just doesn't like the oral cavity.