With what I mentioned above aside, some pretty wild comments on here.
It's widespread knowledge that the receiver, whether that be a woman or man, is at much higher risk of acquiring an STD compared to the penetrator getting one from the person they are having sex with. With male-female sex, including anal sex, their actual exposure to HIV/AIDs is astronomically lower compared to gay men. I don't have the stats in front of me, but the odds of you finding a woman that actually has the disease is very remote. In addition to this, one single sexual exposure does not necessarily mean that you'd become infected, though I sure as hell would never want to take a chance with something like that. As a heterosexual man, I'd be far more concerned about herpes and other common stds than HIV/AIDs.
As for gay men having rampant amounts of sex, I guarantee that is happening, we all understand how the male brain works sexually so no debate on that. There are countless stories of gay men having clandestine rendezvous with other men at parks, rest areas on the highway, etc......which has always creeped me out. I recall reading a while ago that the gay dating app, grindr, has this feature where it shows the location of the person you are talking to, so say you are at a mall you can pinpoint their general area and meetup for who knows what lol. I've read stories on the internet about gay "bath houses" and other creepy venues that are entirely dedicated towards gay hookups. Hell, I can even cite several examples from gyms that I have been to where there have been stories of stuff like this going on in the showers, sauna, etc. I've had a couple approaches in the past, which was one of the reasons why I never would use the gym spa or anything like that, especially later in the evening.