The other day when talking to a guy I like I caught myself playing with my hair, but not the front of my hair, in the back, does it still mean that? Like a sign of flirting? Was I like flirting with him and didn't even know it?
I also twirl the back strands of hair. But I don't think it has to be flirtacious, I play with my hair a lot when I'm just nervous or just thinking, around professors or just chatting to friends etc. I think that if you were playing with your hair among other ways of flirting (smiling/laughing) then it would add up to looking flirty.