a 'normal' person is expected to 'know' when someone wants a bit of rump and tickle, because nowadays most people cringe and think it's highly uncool and unsexy to talk about sex, whereas they are sending off all manner of unconscious signals acting as tests to see if the potential suitor is adequate for the 'job'.
I will probably regret this, but that is one of the few things you have said recently that I actually agree with. It is a big social issue and one that I think affects women too, although perhaps not to the same degree given the accepted social norm of men making the first move, but I think that is changing too. When you throw ASD into the mix (or any complex social personality disorder), it does make the whole thing a lot more complex. Therefore the only viable approach for someone with ASD is honesty.