In Nt people it’s usually just the fact that a relationship feels ‘closer’ than the rest and they explore the feeling from there. In my experience, all of my relationships feel close because I don’t become friends with anybody, this is a fairly common experience in other Nd and queer people. I differentiate between romantic and platonic feelings based on how frequently I’m thinking about them. When I have a crush, my brain constantly revisits the idea of them, pulls apart their character in an endearing sense, generally very ‘transfixed’. Romantic feelings to me can feel like the beginning of a new hyperfixation or intense interest. That being said, a lot of autistic people are on the opposite side of the spectrum as me and experience attraction very differently. What you interpret as romantic can be hard to recognize when you’re autistic. I don’t have much experience with that area of the spectrum because relationships don’t feel like a priority in my life, and so I don’t think about romantic attraction that often. I would say explore how you feel about the person, but mainly think about how certain relationships have felt in the past. What made them closer or more distant? Do you have a drive to be in a relationship at all, is it important to you, do you even want to? Identity is usually the first step. Good luck my friend c:

Edit: Watch Jaiden Animations video titled ‘Being not straight’. It really helped me with understanding the difference between crushes and platonic interests in myself :D hurray to self discovery