There is no simple answer to socialization. I think that is true whether you have autistic traits or not. Sometimes if I am at a bar with the girls, I am likely not looking for romance there. I likely just want to hang out with my friends. Now, that being said, romance can spring from the most unlikely places. I would just be casual, and not make it seem like you are hitting on her. Maybe ask if their group wants to play your group in darts or something. And then you can strike up a conversation with that particular girl from there. Good luck!! !
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"The sun came out, and I walked on my feet and heard with my ears. I hate the bits, the bits that stay down and I work, I function like I'm a girl. I hate it because I know it'll go away! The sun grows dark and chaos has come again."