I'm friends with a girl who is really pretty and smart and an aspie. She's told me about how hard it was for her to learn eye contact, especially because people were always looking at her face.
It's true that the girls might be targeting you for an unpleasant reason, but they also may just like you. You don't have to disclose AS, but I agree with the previous poster that you should say something like, "I'm really uncomfortable with eye contact, so if I look around/down alot, that's why."
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I am a NT sociologist. I am studying the sociology of autism: Identity in ASD/AS, "passing" as NT, and causal effects of NT society on people with ASD/AS.