Most Helpful Girl
I used to actually do the same. I didn't realize that my personality comes off very flirtatious and so finally my boyfriend sat down and talked to me calm saying that it bothered him so I now consciously make sure my actions and words are not perceived incorrectly. Be honest but be light.. don't blame her but bring it to her attention.
Most Helpful Guy
tell her to cut the crap, such behaviour is not toelrable i've met girls like that it doesn't end well, theye flirt with every single guy so tell her to stop or move on and find another girl,