system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why was the AIDS epidemic in America more prevalent among gay men in the '80's?
gpt
Because anal sex is more likely to transmit AIDS than vaginal sex.  At the time, they didn't really know as much about STDs as we do today, so gay men, knowing they had no risk of pregnancy, didn't use condoms.