How do you tell if a smile from a girl is flirty or friendly?

Anonymous
I've always had trouble distinguishing a flirty smile from a friendly smile. the only thing I have come up with is that there is a certain feeling to a flirty smile. However I sometimes get what seems to be flirty smiles from girls who I know are in a relationship. for example there is a teller at the bank I go to who smiles in a way that it feels like it is flirty. one time I typed her name into facebook (I know it's bad) and her profile pic was a pic of her with a man. so I figured she was just being friendly. Then today I went to her to make a banking transaction and again she smiled in a way that seemed flirty. It's very confusing. I guess I want to know how you can tell the difference between a flirty smile and a friendly smile? also what are some other hints that a girl likes you?
How do you tell if a smile from a girl is flirty or friendly?
4 Opinion