Go after a girl with a BF?

I had a big crush on this girl who gave me mixed signals. She has a BF in a diff city (true), but flirted with me in the beginning with this innocent way to talking. I helped her with career advice & she asked me to dinner/drinks. At dinner, she flirted/suggested that I should even go after girls who have BFs. But whenever I reciprocated with the flirting, she backed off, but we basically drank all night in her apartment. Then, she gets me a postcard when she was on vacation. I asked her to dinner, but she ignored my email, only to ask me to dinner 2 weeks later. I thought she was a playing me, so I refused. That week, at a party, she was visibly jealous when I was dancing with other girls. After 5 weeks of silent treatment, I gave in and said hi & at a party she asked me to dance. We got real sensual on the dance flr. She said "I'd like to get to know you", but again gave mixed signals the next day by saying "I'm a ball of ual tension". I find her very attractive. What would u do?