I understand the desire to separate the erotic fucking from the realistic side effects of shit and such. I am mid-thirties now, so I did not experience sex before AIDS was a fact of life. I don't think I ever really came upon the topic of cleaning the ass out until I started frequenting the bareback sites. I would think that it's a rather new concern, as guys cruising the parks, rest rooms, piers, what have you in the past probably had all-natural sex, so to speak.