Daryl wrote:We are obviously talking at cross purposes. You can catch most common diseases by having sex with an infected person, but STDs require sex by any of a variety of ways.
Skin in most cases doesn't need to be abraded, but that helps. Anal sex obviously increases the risk. As Stephen Fry pointed out many gay males don't practice sodomy.
I think yourvery valid point is that it is almost impossible to contract an STD if you are monogamous. More importantly; STDs cannot become epidemic much less pandemic in a culture where monogamy really is the norm. In cultures where the majority of people abstain before marriage, marry young, stay married and seldom commit adultery then STDs will die off.