Haha! There was a video about the corkscrew nature and rapid erections of ducks and how female ducks have vaginas that spiral the opposite way and methods of directing the ejaculate into different . . . crevices? I don't know, somehow the females were able to make sure they weren't inseminated by undesirable mates.
Human mating behaviors are complex enough as it is. Plus, people wear deodorant and perfume and all kinds of fragrant things.
I wish I had a subtle way of letting women know "hey, if you want to get down without any strings, that's cool. Or with strings is cool too. I'm pretty open minded." Without spoiling the mystery.
And also the pre-insertion moment of condom/no condom/I haven't fucked anyone sketchy lately, have you? Oh you're on birth control and never want to have kids/Are looking to get pregnant, etc.
Anyway, drunk evolution seems like it's how we got to this point, but there's something to be said about being straightforward when the situation calls for it.