You don't mention how she flirts exactly. To you it might be flirting, to her it could be just the way she is. Many girls do this and guys take it as "oh i think she might be interested". The whole not looking in your eyes can also mean that because she doesn't find you attractive, she doesn't want to give you wrong idea by pretending you are attractive. If she was interested in you, she would dump her boyfriend before making a move on you..unless of course she's that slutty...In that case, good luck to all parties involved.
-to be nobody but yourself in a world which is doing its best, night and day, to make you everybody else means to fight the hardest battle which any human being can fight; and never stop fighting.- e.e.cummings