Reading people and romantic relationships

100%. I sometimes feel it's the same for me, that I'm better able to pick up deceit or base thoughts or instincts in people than others. 

Well, we're here.  And this means that, at some point, the biological imperative to reproduce brought us here.  So I'd say that, irrespective of our ability to read people, we are genetically loaded to respond hormonally and that there's a kind of "knowing" when we feel that response is returned.  

Mind you, I'm not entirely convinced by the psychiatrist.  My experience is of reading people too well and of this sometimes feeding into my fears and anxieties if I can feel their intent is a bit "off".  And then I'm suspicious of non autistics telling us we're somehow lacking when they so obviously misinterpret quite a lot of autistic people. 

The double empathy problem should be something of which psychiatrists are aware.   www.youtube.com/watch

Sexual attraction works on such a primitive level of the brain - inclding the olfactory system (pheromones) - that I doubt if autism has any great effect on it. Romance is a largely sociological and cultural layer added to sexual attraction, and many societies throughout history operated without it, from a who marries who angle. I would imagine that most autistic people recognise to whom they are attracted with the same facility as allistic people. The problem for autistics is the limited ability to recognise when others are attracted to them.

I think you would know if you liked someone enough to want to spend lots of time with them but maybe you might need to get to know them first rather than in movies etc when people just look at each other for the first time and fall in love. My issue is more with realising that people like me, I usually have to be told rather than picking up on flirting and hints

I believe in the distant past, I probably did have a fairly good notion of who I was interested in romantically; and I also had a fairly good notion that most others were not particularly interested in me romantically. I eventually 'married' someone; but our relationship tends to be rather more practically-orientated than romantically-minded. After that 'marriage', I did experience one person who claimed to have fallen in love with me, but it was not at all reciprocal, in my case; perhaps because I really could see that it would have been a highly incompatible relationship, and have been extremely impractical within my existing 'convenient' relationship. In any case, I rather defy almost anyone here to really begin to understand romance. Perhaps at least part of the romance is in some of the practicalities, for instance.

I'm a bit too old to 'fall' in love now. However, that doesn't mean to say that physical and even emotional attachment isn't possible; it's just not at all practical in most cases. I'm not actually completely against so-called 'open' relationships. I still feel like I'm about twenty years old. But after decades of mutual disinterest and noticing the impracticalities of it all, I have probably already inactivated the romance option.

I would suggest that at least some of us are actually fairly good at 'reading'. but that we are so often 'misread', that we can no longer be bothered with heavy romance. I'd probably be more interested in just having a bit more 'fun' these days. I suppose some people might call that a mid-life crisis, but I also suppose that it doesn't really have to be that way. I also suppose I'll just continue to see what comes my way; as has always been the (practical) case. I won't go out of my way to make it happen. And it almost certainly won't happen; that's my experience so far. But I also won't do anything to avoid it happening.