The terms 'insertive' and 'receptive' tend to be used in the medical studies that discuss sexual exposure to HIV. Since these studies tend to focus on penile-vaginal, penile-anal, and oro-penile sex, the terms 'insertive' and 'receptive' are fairly intuitive. With oro-vaginal or oro-anal sex, however, they are less intuitive.
Although HIV infection can go either way (from receptive partner to insertive partner, or vice versa), the 'receptive' partner is NOT the one receiving the 'sexual act'; rather, the receptive partner is the one who is potentially receiving more infectious bodily fluids and thus has greater potential for acquiring infection. The insertive partner is the one who is the source for the greater amount of potentially infectious bodily fluid.
With oro-vaginal sex (cunnilingus), there is no practical HIV risk for either the insertive or receptive partner.
Wouldn't the insertive partner be the giver
and the receptive partner be the 'taker'?
So you are saying there is no risk to the
one on the receptive end, but there is some
risk for the giver?
No. HIV is not transmitted to the 'insertive' partner (in this case, the woman receiving cunnilingus) by oro-vaginal contact.
Saliva is not infectious.
Even if the receptive partner were bleeding profusely in the mouth, there are substances in saliva that inhibit HIV.
Even if infectious blood-saliva mix went from the mouth to the labia and vagina (e.g., through digital stimulation), the chances of transmission would be infintessimal.
There are no documented cases of HIV transmission by cunnilingus.
There is one suspected case of HIV transmission by cunnilingus (it was a lesbian couple), but doctors were unable to eliminate other potential risk factors (such as IV drug use or unprotected male-female sex).