Go back to ex gf or get a new one?

[MechaDrone]

Hey, My ex gf is giving me some signs that she might be interested in me still. But she has a new boyfriend which is a rebound relationship, she always talks to me first on the bus and such and looks at me. I heard she looks at me when I'm not looking and smiles and also heard that she got jealous of a girl for liking me for some odd reason and another crazy thing she tried saying I cheated on her which I never did in my life, in the past, she told me that she doesn't like me anymore and such but she is making a lot of signs to me that there is another chance for me and her. On the other hand, there is this other girl who I like more than my ex gf. She is a sweet girl who has talked to me a lot more since one of my friends told her that I liked her. A while before, me and she held hands for like 4 times before. Me and her tease each other and calling each other some nicknames which aren't bad at all and me and her at prom slowed danced together, she even asked lol I was very glad she asked, I caught her a few times looking at me and she usually talks to me first.

 

I'm just wondering which would be better, If I try to go back to my old ex gf or go for the girl who I slowed danced with and if there is even a chance. Thanks!