So I know this girl which I am trying to hit on but I get mixed signals from her. When we party together with a big group of people she always flirts with me and plays around. When we meet at school or some other place 1 on 1 she is always passive. Like she is always tired or something, doesn't really talk much etc. I am not a big talker myself but I do like to flirt with girls but our normal conversations are pretty stale. What does it mean and what should I do?