Всё зависит от КАКОГО секса имеется в виду. Or to more blunt about it, the question is: Куда входит член? (And I mean куда in the sense of "в КАКОЕ отверстие?", and not "в ЧЬЁ отверстие?" (мужчина или женщина).
According to the American Center for Disease Control (CDC), the HIV risk for unprotected anal sex is about 5 times higher than the risk of unprotected "traditional" sex (член/владище). And the risk of unprotected traditional sex is about 10 times higher than the risk of unprotected oral sex. Which means that anal sex without a condom is about 50x more risky than oral sex without a condom. In more general terms, we can compare the risk levels as follows:
Anal sex = HIGH risk
Traditional sex = MEDIUM risk
Oral sex = LOW risk
Mutual masturbation = "STATISTICALLY ZERO" risk
Also, HIV can easily be passed from a man to a woman, but much less easily from a woman to a man. In the case of anal sex between two men, HIV most often passes from the "Top" (активный) guy to the "Bottom" (пассивный) guy, and much less often from the "Bottom" to the "Top."
So, in the event that a female porn actress has HIV, it's relatively unlikely that she will pass the virus to a male actor, who might then pass it to other females. (Female-to-female transmission is EXTREMELY rare.) And if the males in straight porn are strictly heterosexual and don't use heroin by needle, then it's unlikely that they will catch HIV and pass it to their female co-stars. It's true that some "heterosexual" porn actors will take "gay for pay" roles in gay porn, but they nearly always take the role of "Top," so again, the chances that they will catch HIV are low.
So for all these reasons, unprotected sex in straight porn is not quite as dangerous as unprotected sex in gay porn.