I say if chick 2 is deciding between you and some other guy-make the decision for her and bail. You'd be suprised-about 95% of the time, she'll start to think and probly think she wants you!
This 1st girl-just ask her what happened and what she thinks about that guy and what she thinks about maybe you and her hookin up.
Also-game tip- loosely mention to chick 2 to chick 1- jealousy usually comes in and that also helps her decide you.
Take it or leave it.