You should watch the documentary Gay Sex in the 70s. Really watch it. One of the conclusions I came away with was that some kind of extremely troublesome STD

You should watch the documentary Gay Sex in the 70s. Really watch it. One of the conclusions I came away with was that some kind of extremely troublesome STD was going to emerge from that particular situation. It happened to be HIV but it could have been something else entirely. Anything where you have big globs of people exchanging bodily fluids over and over again is going to encourage the development of something infectious. It's the same reason that preschool tends to be a germ pit. If someone invented a sport called, I don't know, "Loogie Frisbee," where people stood around and took turns spitting into each other's mouths, I would expect some kind of oral infection to take off as the sport went pro.