Why do they do this? I talk to a girl often and she ends up doing this. It's kind of strange? I was wondering whether it was anxiety but she seems confident?

Do any of you have experiences of this?

I wouldn't take it as meaning anything...

She's grooving to the invisible beat of the sexy sexy music

No

I would'nt concern yourself with this unless she starts rubbing her pussy with one hand and feeling her left tit with the other usually a strong sign, but double check the position of her feet to be sure.

She's bored.

She's having a stroke...

on the basis that your feet move towards your train of thought, her feet wer lookin at goin walkies

You have to be very special to miss that, i won't even consider to be an IOI.