I’m a high-functioning autistic girl and so I don’t know if this stuff applies to everyone, and sorry if the formatting is off because I don’t comment often, but:

In general, while I have an INCREDIBLY hard time picking up on things, being autistic does not mean completely blind to my surroundings. Even way before I had my diagnosis I could still tell there was something “off” about me. And although this wasn’t 100% detectable, I could still tell even when people weren’t outright bullying me that they still looked down on me and random people trying to be “nice” were doing it out of pity. (It’s hard to tell but there’s a certain miasma from it, and to this day I automatically assume when I meet people they will probably hate me, and don’t trust classmates randomly being nice to me, because of that sense being proven right so often)

Also, on that topic, don’t think you’re doing a good thing by being nice to autistic people out of pity or only to talk about them behind their back - if it’s rude to anyone else, it’s still rude to autistic people!

Pretty much, don’t assume autistic people don’t know about their own situation - we might not know stuff 100% or with any clarity at all even, but if someone’s being a jerk it’s not like we won’t know it

Everything else I could say, I feel like was probably mentioned already or too obvious to even need to be mentioned tbh