When it comes to flirting, guys in general, NT and Aspie, are pretty bad at reading the signals.
They did a study on this (presumably on a mostly NT sample)--
Guys in general were wrong 50% of the time, meaning that half the time, when they thought a girl was flirting with them, she was just being nice, while the other half of the time, when they thought she was just being nice, she was flirting.
Women, meanwhile, had much closer to a 90% detection rate. It goes back to the gender-specific skills we have, the way our minds are developed, the much more social world of women, etc.
Aspies, however, tend to have it a lot worse -- their detection rate, which I don't have figures for, but can guess based on personal experience and observation here, seems to be more like 10% and under. Not sure if there's any difference in gender.
When it comes to coping and life skills, it would seem this is the one that anyone who is lonely or concerned about not attracting the opposite sex needs to take very seriously. We all have to make adjustments and effort for other general social things, but this is a deep source of a lot of dissatisfaction here, so I do think it merits particular attention and focus.