Haha, another Question

Ok, this "new" girl that I like we were supposed to go to the movies on Sunday, that didn't happen because she said she "forgot" she had work, and that her sister was coming home from Montreal that day. So I bought it, so then today I was like, "So, when ya taking me to the movies?" She was like "I am not sure if that would be right.." Then I jokingly said "is your long lost cousin coming home from Peru?" She laughed, so I started to walk away, and she was like "want to know my reasons" I said ok, then she was like "I'm seeing someone" .. This sort of pissed me off. She flirts with me, leads me on, tells me that she wants to hang out, etc, but then says this?

My question would be:

Is she just trying to be nice to me, and she's not interested at all ?