your friend's ex... off limits?

so, i've been friends w/ "bill" for a long time. bill and i lived together during school with 3 other people. he dated "veronica" for almost 2 years. bill met veronica freshman year of college, and sophomore year veronica transferred to another school because they had broken up and veronica's life at her first school basically revolved around bill. a few months later, veronica and bill got back together..

back in march/april, they broke up because veronica made out w/ a couple guys. (once on spring break, don't know when the other was) she says the reason she did it was because he treeated like her [censored], which he did. he cheated on her a couple times, but never told her.

SO, he broke up with her and a few weeks later he started dating another chick. fast forward to september-ish. bill and his new chick broke up for a little bit so he calls veronica and he goes up to see her and they fool around. (she was always telling me things he'd say to her.. recently he told her that he missed having sex with her and that he has to fake 1/2 his orgasms w/ new chick - when he first started dating new chick he would always tell veronica that he missed her and that sometimes he wishes new chick was veronica) i can't decide if he says these things because he's just trying to teach her a lesson, or he actually still loves her, or if he just enjoys having veronica be depressed over him..

fast forward to last month - veronica and i have become really good friends, we talk all the time and have a lot in common. we were friends when she dated bill, but never really talked all that much. so some friends and i were up visiting our other friends and i eventually met up with veronica. i ended up going home w/ her and all we did was make out. a few days ago we were talking and she told me that she liked me, and i told her i liked her.

so, what's my play now? i really wanna hang out with her and see if there is something between us - what if there is? do i pursue something? should i get 'permission'??

any advice is appreciated