People on the spectrum struggle to understand the meaning of non-verbal social cues. Unfortunately, this can be very hazardous when it comes to inter-personal relationships, especially those of a romantic nature.
I used to think I had a chance at a relationship with someone as long as they didn’t flat-out reject me. What I failed to understand was the non-verbal cues, i.e. not returning phone calls, not being receptive to conversation. But while these things may not come easy to the Aspie, they can certainly be taught.