Should I? Or shouldn't I..?

I dated this girl few months back, it sucked- b4 we went out and b4 I left my previous girlfriend we hit it off real nice, even though I was preparing myself from getting s to holding hands with a chick who never kissed a guy seemed, well, stupid. I was determined, I loved her. Before the break up and new relationship we were touchy feely, my hand would be casually on her long y legs, or my fingers would casually locked with hers, hand in hand as if I didn't already have a girlfriend who was giving me s as we dated for two years. So I got with the new girl for 3 weeks, it sucked. Sent her flowers to her house, she said thank you- was happy for 5 mins and went back to being pissy and constantly picking a fight... I did whatever she asked, acted whoever she wanted, I was determined to please her. Months after the break up at MY party she comes off so y, obviously I'm still attracted, only after she shakes her *** flirtatiously on the dance floor with me. We make a perfect couple, one problem, she's not honest, afraid, always avoiding when something has potential to be awkward. I'm straight up, I'm also confident and aware that I could please any women. I asked her to my halloween party: she has "other plans." but since everyone is going (including all of her friends) she wants to come, *she didn't tell me- her friend did* that's what bothers me, thats what turns me off, that is not a model relationship in my book... what can i do? What should I do? Should I get back with her?